Britbike forum Forums Projects started by Britbike forum members Members bike projects Rewiring a Motorcycle

INDEX
-- this is a placeholder for now --
Overview
Introduction
Wire

Tools and Supplies
--Wire Strippers
--Wire Cutters and Electronics Pliers

Tools and Supplies (continued)
--Soldering Irons
--Solder
--Soldering Accessories

Tools and Supplies (continued)
--Solderable Lucas-Type Bullet and Spade Connectors
--Crimp Lucas-Type Bullet and Spade Connectors
--Crimp Connectors
--Non-Insulated Connectors
--Crimpers

Tools and Supplies (continued)
--Heat Shrink Tubing
--Heat Gun
--PVC Sleeving
--Split Sleeving
--Wire Ties
--Electrical Tape
--Dielectric Grease
--Contact Cleaner

Tools and Supplies (continued)
--Electronic Instruments

Wiring Diagrams

LED Bulbs

Using the Frame as Earth/Ground

OVERVIEW
My basic assumption, at least as I start this thread, is it will be limited to how to completely rewire a British motorcycle. I won't address issues like converting from 6V to 12V, changing to electronic ignition, etc. although such topics might get added after we're done with the basics of wiring. However, topics like rebuilding a dynamo or Lucas voltage regulator deserve their own threads, like the magneto.

Since information only is useful if it can be found, I'm going to try to keep things organized in a way that will allow me to create an index at some point, as I did for my magneto restoration thread. However, since anyone with something to contribute is encouraged to post to this thread maintaining a structure to it will be a challenge. I can imagine copying complete posts and pasting them where needed to keep the organization simple so we could end up with some duplication. In a sense my posts in this thread will be like Wikipedia in that I will revise old ones in light of relevant new posts. The "Edited" date is at the bottom of each post but note that only the latest revision is listed, not (possible) earlier ones. We'll have to see how structure develops as things evolve. Aside from this, some of the information is copied from a thread in a different forum that lead to the current one.

The origin of this thread was being asked to rewire a friend's BSA ZB34/M20 hybrid. Since I did that fairly recently I remember most of the tools and supplies I needed for it, but I may return to some early posts and add things I had forgotten once I start rewiring another bike.

INTRODUCTION
Basically, there are three approaches to rewiring an old motorcycles: 1) buy a reproduction wiring loom; 2) make your own using soldered or crimped Lucas-type bullet connectors, or 3) make your own using other types of crimped connectors. Although this thread deals with choices 2 and 3 it's likely that even a high quality wiring loom may need modifications.

A further choice is to use wires with the original colors shown in the wiring diagram, or make up your own color scheme, possibly even using the same color wire for all connections. I strongly recommend against the latter, although I realize some people will do this anyway. But, we will return to this later.

WIRE
Since wire is the most basic component of rewiring, let's start there. I went through wiring diagrams for AJS/Matchless, BSA, Norton, Triumph, and Vincent and identified 48 colors of wires used in the '50s and '60s. I can't guarantee there aren't other colors as well, but there probably aren't many more than this. It turns out that Autosparks in the UK, and their U.S. agent British Wiring carry all of these wires in the necessary sizes.

For our purposes the three relevant wire sizes offered by Autosparks with 'standard' thickness insulation are: 44/0.30, 25 Amp; 28/0.30, 17 Amp; and 14/0.30, 8.75 Amp. The first number is the number of individual strands of copper wire in the bundle, the second is the diameter in mm of those strands, and the third is the nominal safe current carrying capacity. Since all three of these examples have the same strand diameter the difference in rated current is due to the number of strands and thickness of the insulator.
As Stuart pointed out in a subsequent post, partially copied here, there can be advantages to using the smaller OD 'thinwall' wire from the same suppliers, especially for later bikes where more wires have to fit into a given space.

Autosparks gives the approximate conversion of these to the U.S. AWG sizes, and from that the wire table gives the resistance per foot of the wires as follows:

14/0.30 ___ 17 AWG ___ 0.00506 Ohms/ft. (measured 0.00590, i.e. equivalent to ~17.6 AWG)
28/0.30 ___ 14 AWG ___ 0.00252 Ohms/ft. (measured 0.00307, i.e. equivalent to ~14.8 AWG)
44/0.30 ___ 12 AWG ___ 0.00159 Ohms/ft.
(note: in earlier versions of this, and in a different thread, I mistakenly used values of Ohms/m in place of Ohms/ft resulting in apparent power loss in the wires being ~3x larger)

Fair warning to those in the rest of the world, in most of this thread I'll use AWG designations for wire sizes. It's easier to write and many of the required solid colors are sold less expensively by other vendors in AWG sizes.

In the case of a 6 Volt machine, assume the wire that carries all of the output from the voltage regulator under the seat to the switch in the headlamp housing is 4 ft. long. At a nominal 6 Volts and at full output a 60 Watt (V x I) dynamo generates a current of 10 Amps. The power loss in the wire itself would be (10 Amps)2 x resistance/foot x 4 ft. This loss depends on which of above three wires are used, giving the following:

wire______ power loss ____ percentage power loss
14/0.30 ____ 2.02 W __________ 3.4%
28/0.30 ____ 1.01 W __________ 1.7 %
44/0.30 ____ 0.64 W __________ 1.1%

Stepping up one size from 14/0.30 (17 AWG) to 28/0.30 (14 AWG) for this particular wire cuts the losses by a Watt. Taking it another step to 12 AWG would save an additional 1/3 Watt, but at the expense of a stiffer wire. For this reason I used 28/0.30 (14 AWG) Brown/White wire on the ZB34, although someone else might reasonably decide on the 44/0.30 (12 AWG) should they want every milliWatt delivered to where it can do some good.

One more note on wires, all other things being equal, changing from 6 Volts to 12 Volts reduces the current by half since I = V/R. That in itself doesn't matter, but what does is the power loss in the wires and at the connections since it goes as i2R. Half the current means 1/4 the losses. However, as noted above, as more wires got added starting in the 1960s the space they took up increased so 'thinwall' wiring can be a useful upgrade. Despite the higher current rating, the power loss per unit length is the same irrespective of insulation, but the smaller diameter is an advantage when the space is limited.

The longest wire subject to constant current flow at night in a 1950s machine is Brown/Green from the headlamp shell to the tail lamp. Assume that length is 6 ft. The bulb itself is 5 W, which I'll call 6 W since that means the current draw would be an even 1 Amp. With the smaller wire size of 14/0.30 the power lost in that wire will be (1 Amp)2 x 0.00506 Ohms/ft. x 6 ft. = 0.03 Watts. Even though the current draw is constant the loss in the wire is so small that I saw no reason to use a larger wire here.

For what it's worth, I chose to buy 8 meter (~25 ft.) rolls of all 48 colors, which I estimate will give me enough of any given color to completely rewire a minimum of approximately 5 complete motorcycles. All the wires were 14/0.30 (17 AWG), but with additional 8 meter rolls of the following colors in the larger 28/0.30 (14 AWG):

Brown
Brown/Blue
Brown/Green
Brown/White
Green/Brown
Purple/Black
Red/Blue
Red/Brown

I also sorted through my other wires to locate the "motorcycle colors" I had in useful sizes. My current wiring situation is shown in the next photograph with the solid colors in 16 AWG and 12 AWG in the box on the left and the British Wiring wires on the right.



Note that the resistance/foot I measured for two sizes of wire supplied by Sparks and British Wiring, listed above, are equivalent to ~17.6 and ~14.8 AWG. This means that someone today crafting their own loom using wire from other sources could use common (in the U.S.) 16 and 14 AWG as suitable substitutes for them.

Although it's likely that I will never use many of the uncommon colors, I wanted to have all of them on hand "just in case." Clearly, most people will only want to buy the wires required for whatever bike they are working on at the time, and those colors are to be found in the factory wiring diagrams. I decided on 8 meter lengths since that would be enough for a minimum of approx. 5 complete rewiring jobs using the most common colors (e.g. Brown/Green for the line from the headlamp shell to the tail lamp), so most people will need less than this.


TOOLS AND SUPPLIES
Not all approaches require the same tools and supplies but the ones in this section should cover all possibilities.

Wire Strippers
Until the insulation is removed from the end a wire can't be connected to anything. Wire strippers come in several varieties, with examples of ones I use shown in the next photograph



While the two at the right are useful when rewiring a motorcycle, for nearly everything I use the two at the left. These are of the same design but are made to handle different sizes of wires. One jaw grips the wire when initial pressure is put on the handles and the other jaw cuts into the insulation. When additional pressure is applied to the handles the jaws separate and take the insulation with it. The advantage of these is they strip a wire without the risk of tugging on whatever is at the other end of it.

Wire Cutters and Electronics Pliers
The top row of the next photograph shows several useful wire and cable cutters, and the bottom row needle nose pliers.

It's best to use the largest cutter possible since that minimizes wear on the tool, but there is no substitute for small cutters when reaching into tight spaces. Similarly, when cutting large wires or cable, like a spark plug wire, there is no substitute for a proper cable cutter as shown at the right of the upper row.

Needle nose pliers are used for several purposes when rewiring a bike, so they need to be in several sizes. Perhaps not too clear from the photograph is the two pliers at the far left have tips that bend upwards at the end, which can be quite useful.

[to be continued]

Needing--I believe that this thread will turn into THE definitive reference for Brit bike rewiring for years to come.
Any mention of costs will therefore be out of date quite quickly in comparison with the life of the reference thread.
Anyone reading this forum has access to a computer and the internet so that references in the thread to sources of materials, tools etc can be readily followed up at the time to get then current prices.
HTH

Good initiative, Magnetoman.


Also, a price for a part in the USA in USD contains USA taxes.
The same item in any European country or in Australia or whereever, is influenced by local taxes, and is most likely not comparable with a conversion factor only.

Good thread. Needs to be turned into a video / DVD and sold on e-bay.

Soldering Irons
Even if you plan to use crimp-on connectors it still is likely you will need to solder something on the bike. A simple 40 Watt soldering iron is all that is required for nearly everything on a motorcycle, but the next photograph shows other options, each with advantages for some uses.



At the left in both rows are straightforward soldering irons. However, the one with the red handle in the top row is only 25 Watts which is really not enough power for most tasks on a motorcycle. Starting at the left of the bottom row is a conventional 60 Watt iron. Next to it is a 50 Watt Weller WESD51 digital soldering station. Its advantages is it allows the tip temperature to be set at the ideal value for whatever composition solder is being used, with the unit automatically sending the necessary power into the tip to maintain this temperature independent of whether it is being used to solder something small or a large piece that requires more power.

At the right is a dual range 40/100 Watt soldering gun. It's clumsier to use than an iron on most items, and its larger tip means it can't be used in restricted locations, but I've had it since high school and the upper range is quite useful, especially for some desoldering tasks. Not shown is my dual range 200/260 Watt soldering gun. It looks essentially identical to the one shown and, although I can't remember needing the extra power for any wiring task on a motorcycle, it's worth mentioning that high power units are available in case someone need them.

Last, at the right of the top row, is a butane-powered soldering iron. This has the advantage of being able to work where a cord is inconvenient or electricity isn't even available. These come in different sizes and powers, and the one shown in the photograph is equivalent in power to a ~100 Watt electric soldering iron. It is very handy. Including it here is the first sign of mission creep of this thread, since one could easily get by without it when rewiring a bike in the garage, but it is indispensable for emergency electrical repairs in locations away from electricity.

Solder
Solders containing a variety of elements are useful for various purposes. However, for electrical and electronics work the best solder to use is 63/37 or 60/40 with a rosin flux core. The numbers refer to the percentages of Sn and Pb. Often only a single number is used, e.g. "60", in which case it refers to the composition of Sn, with Pb making up the rest.

Since Sn is more expensive than Pb if you buy solder from a random supplier the risk is it won't have enough Sn in it to work properly despite whatever is printed on the label. The next slide shows some examples of appropriate solder.



The wire on all three spools is 60Sn/40Pb, hollow, and filled with a rosin flux. Because of this, no additional flux is needed, nor should it be used. Having said that, at the right is a stick of rosin core flux that sometimes in certain circumstances can be helpful. However, it is not necessary. Many soldering fluxes, such as used in plumbing, are acidic and will slowly damage a connection if used and not completely removed afterwards.

The wire on the spool at the left has a diameter of 0.020", and the one next to it is 0.060". The first is a little small for our purposes, although it would be fine if that is all you have. Smaller just means you have to feed a longer length of solder to deliver a given amount of it to the joint. The larger diameter wire is perhaps a bit larger than optimum (although for years it has been the one I reach for first), so I would recommend ~0.040" or ~0.050" if you have a choice. But, anywhere in this range is fine.

Lead is in the news because of the water supply in Flint, Michigan. It is a heavy metal and has undisputed neurotoxic effects so there are very good reasons to get it out of our drinking water and house paints. Because of the toxicity of Pb a lot of effort has gone into finding suitable replacement solders for the electronics industry, and lead-free solders are becoming increasingly prevalent. I do not recommend using them because they don't perform as well as Sn/Pb.

Ingestion of Pb, rather than absorption through the skin, is the issue to be aware of. For what it's worth, I understand and respect the safety hazard of Pb but I hold solder with my bare hands. However, I wash my hands before eating (because that's what a gentleman does), don't snack on potato chips while working, and I don't chew my fingernails, so the ingestion hazard isn't large. Read about Pb and make your own decision, but I hope we can skip any further safety discussions about Pb because they inevitably descend into rants and raves about Nazi bureaucrats taking away our freedoms.

Soldering Accessories
The next photograph shows some accessories that make life easier.



At the left is a "solder sucker." Its tip is held next to a molten pool of excess solder and the button pressed to release the spring-loaded plunger to suck the solder into it. The two coils of copper braid accomplish the same thing by wicking excess solder onto the braid which is then cut off and discarded. The clips and tweezers on the heavy bases are very useful for holding and positioning wires and items with respect to each other, freeing up both hands to do the soldering.

[to be continued]

Thank you. Just what I needed, and at the right time too.

Hi,


This thread is a great idea and your first post is a good start but, if "Tridentman" Richard's "this thread will turn into THE definitive reference for Brit bike rewiring" is to be true, it's starting to fail your statement in your "Overview" - "how to completely rewire a British motorcycle"; ime, it's already leaning towards 6V and 1950's electrics without actually saying so.

I have some experience of those but greater experience of 12V and 1960's, 1970's and 1980's electrics. I followed your thread about rewiring the BSA ZB34/M20 hybrid; I would not have done some things you did but, as you had done them before you posted, I didn't see any point posting anything else there. However, as you want this to be about "how to completely rewire a British motorcycle" without DC Voltage or age qualifications, imho the differences are valid here.


These are wires with 'normal' PVC insulation; ime, in 44/0.30 and 28/0.30, thinwall is superior.

For those that are reading this but didn't read MM's ZB34/M20 rewiring thread, 'thinwall' wires use a different plastic to insulate, which results in both a thinner overall diameter and a higher rating for the same conductor size. I appreciate that the higher rating might not be of interest to many Britbike owners, the reduced overall diameter should be.

Singly or in the context of minimal 1950's wiring, the overall size of individual wires might not matter but, on later bikes and/or if you incorporate some of the improvements that will be posted in this thread, ime the reduced overall diameter of thinwall is useful. From lengthy first-hand experience of using wire with both types of insulation, when 44/0.30 or 28/0.30 is being fitted, I would always fit 'thinwall' (if referred by rating rather than conductor size, the respective ratings are 33 Amp and 25 Amp).


Which again rather limits the thread's usefulness, particularly if it becomes a long one? Apart from AWG is meaningless to the vast majority of the rest of the world, are the "solid colors sold less expensively by other vendors in AWG sizes" really AWG? There are lots of wire makers in the US still manufacturing using AWG? Or these US vendors get their wire from the same (Far Eastern?) makers as the rest of the world but just 'convert' the real metric sizes for their US customers?

Regards,

http://www.rapidtables.com/calc/wire/awg-to-mm.htm#calculator

gives a nice conversion tool from AWG to [mm].

Well, yes and no. I didn't explicitly mention 12V (but have corrected that now with revised text), but what matters is current flow and resistance, not voltage. Yes, I, V, and R are related, but the power loss in a particular wire carrying 10A is identical whether it's in a 6V or a 12V system.
As I wrote in my first post, people are encouraged to contribute even though it will make organizing the thread in a way that can be usefully indexed more difficult. I've taken the liberty of incorporating the above in the section on "wire."
I have to gently disagree. It's true that if I quote some relevant specification in oF it makes it less useful for most of the world, however a calculator to convert to oC is only a click away., as it is for inches to mm, miles per hr to kph, pounds to kg, etc.

Disclaimer:
While I hope TM's comment is prescient, I make no promises...

This is an interesting question that just cost me an hour to investigate.

In my box of solid color wires are rolls of 12 AWG in four colors. On the wires is printed a lot of information including "Made in USA" and "12AWG." These are made up of 19 strands of 0.018" dia. wire, for a total area of 3.0 mm2. Within the uncertainty of measuring the wire with calipers instead of a micrometer the wire tables confirm this is 12 AWG.

In a packaged labeled "Noble Wire & Terminal Company, Made in USA, 16Ga, 50 Volt max." is a ~25 ft. roll with no markings on the wire itself. It has 19 strands of 0.27 mm wire whose total cross section of 1.09 mm2 makes it ~16.7 AWG.

A set of spools of wire in multiple colors I probably bought on eBay doesn't have a country of origin marked but it does have "16AWG ... 300V 105C" printed on the wire. Its 26 strands of 0.23 mm wire give it a cross section of 1.09 mm2 also making it ~16.7 AWG. Taking the claim at face value that the spool is 25 ft. the measured resistance is 0.1106 Ohms, vs. the 0.1004 Ohms it should have if actually 16 AWG (but 0.1266 if 17 AWG). From the resistance (and assuming it really is 25 ft) the size is ~16.5 AWG. That this agrees with the cross sectional measurement means the "25 ft." roll I paid for is actually 25 ft.

I have more wires I could measure, but I already have enough information to conclude that the only way to know what you have bought is to count the wires in the bundle and measure them with a micrometer to determine the size in whatever units you prefer (AWG in the U.S.). After doing this you have to measure the total resistance with a milliohmmeter to determine whether the length you paid for is the feet/meters you got.

Or, decide that for present purposes if it looks and feels like the right diameter then just trust that it is, or that it's close enough. Having said that, beware of aluminum wire being passed off as tinned copper because it has significantly higher resistance.

Finally, I measured one of the "8 meter" rolls I bought from British Wiring and found the length to be a generous 8.53 m and the resistance to be 0.1652 Ohms, i.e. 19.37 mOhm/m. According to the wire tables this makes it equivalent to ~17.6 AWG. And it indeed does have 14 strands of Cu wire in it that my micrometer confirms are 0.30 mm in diameter.

Please, it's not helpful to post random images from catalogs and of irrelevant trailer connectors. It just adds clutter to the thread without contributing anything useful.

Lamp cord, household wiring, power cords from old computers, etc. all can be made to function as motorcycle wiring so they are "suitable" in the same way trailer cable is.

My hope with this thread is to describe how to do a "professional" wiring job on motorcycles that is to the equivalent standard as a "professional" engine rebuild, or any other quality mechanical work. Not necessarily "concours," although that's included, but in any case "professional." If you want to insist trailer wiring can be used, this thread is not for you.

Just because it is an "automotive product" doesn't mean it is appropriate for our use. In this case, it most definitely is not appropriate. Trailer cable has a very thick sheath because it dangles in free air and is subject to a lot of wear and abuse. The one on my trailer is 1/2" OD and carries six wires. In contrast, five 17 AWG wires fit in an appropriately-thick PVC sheath that is only 1/4"-dia., i.e. roughly only 1/4 the volume.

Not only is the trailer cable massive by comparison, the task isn't to run six wires all the way from the headlamp to the taillamp, but rather to be able to bundle together the wires that are needed for a short run while splitting off ones from that bundle at various places to go to accessories like horns and brake lights. A trailer cable is not easily split, and even if you tried to do it, odds are whatever color wire you were looking for wouldn't be adjacent to the opening you just made. Then, how to pull the, say, green wire from the tight bundle to take it to the horn?

I quickly gave up on your posts on modifying an AMAL Concentric because what you wrote in them showed a profound lack of understanding of how they functioned. However, no matter how many people told you that, you were relentless in continuing to post. Please don't continue to do the same thing here. It only makes the thread harder for people to read, and irritating for others. For now, unless the moderator blocks you, all I can do is ignore whatever you write.

Solderable Lucas-Type Bullet and Spade Connectors

I wouldn't be surprised if there were variations in the bullet connectors made by Lucas over the years, but the next photograph shows ones that probably date from the mid to late-1960s.



Also shown in the above photograph is the mating "snap connector" after removing it from the insulator. The important points to note are the small depressions in the connector that retain the bullets by the grooves in them, and that electrical contact is made by the cylindrical section at the "rear" end of the bullet.

The ODs of several Lucas bullets were ~0.185" and the ID of several snap connectors ~0.180". Because this difference is small the distortion of the snap connector is small when the bullet is inserted resulting in good contact around the circumference. Without cleaning or abrading I measured the contact resistance of several Lucas bullets and connectors and found them to be less than 0.1 mOhm, which is negligible. If 10 Amps were flowing through the connector (i.e. delivering 120 Watts to a load at the other end) the resistive loss in the connector would be (10 A)2 x 0.1 mOhm = 0.01 Watt. Even if there were ten such contacts in this circuit the total loss would be only 0.1 Watt.

The next photograph shows bullet connectors from three sources.


At the top is a Lucas bullet, followed by a solder-type bullet from British Wiring, a brass solder-type from eBay, and one of those brass bullets inserted in a Lucas snap connector. The OD of the Lucas bullet is 0.185" and that of both of the aftermarket ones is 0.188".

Note the wide groove of the brass bullet. This bullet is shown pulled back against the depression in the snap connector, i.e. retained by the depression but at the position of minimum contact of the cylindrical section. As can be seen by comparison with the first photograph less than half the contact is made. Consistent with this the measured electrical resistance of this contact was ~5x larger than of the Lucas bullet. However, although I don't understand why the manufacturer decided to make this groove so wide, even this worst-case resistance is negligible.

To understand how Lucas soldered the wires to their bullets I simply unsoldered one of them, as shown in the next composite.


As can be seen from the top of the composite the wire extended ~0.02" through the hole in the "nose" of the bullet and wicked solder up a distance ~0.1". The OD of the wire is 0.042" and the ID of the hole in the nose of the bullet is 0.060" so the ring of solder connecting the two at that point is 0.009" thick. The holes in the British Wiring and brass bullets are larger at 0.073" and 0.082", respectively, which would result in somewhat lower mechanical strength because of the thicker cross section of solder.

Although it appears that the entrance of the bullet is crimped to the insulation of the wire this is deceptive. The OD of the wire is 0.103" and the ID of the entrance to the bullet is 0.116" so there is no mechanical connection between the two. All of the strength of the connection is provided by the small amount of solder. Think about this the next time you're tugging a wire to pull it loose from a snap connector.

To understand more about how the wires were soldered the next micrograph is of a bullet that I crudely sectioned with a hacksaw blade.


I hope it is clear that solder extends from the "nose" of the bullet to the groove. The next micrograph shows just the tip of the nose of another bullet showing solder has wicked a short distance up the outside.


Piecing this information together, Lucas stripped the wire, dipped the end in flux, inserted it until it projected ~0.02" through the nose of the bullet, and then applied solder that wicked a distance ~0.1 up the wire to provide both the electrical and mechanical connection. This resulted in connections that withstand vibration and whose resistances cause negligible dissipation. Our goal in wiring a motorcycle should be to do at least as good as this.

Before ending the subject of Lucas female "snap connectors," these are found as singles (for connecting two wires) and doubles (for connecting either three or four wires). Triples, quadruples and even quintuples also are found. However, starting with triples the sockets either can be all electrically connected with each other, thereby connecting all wires plugged into the sockets, or they can be electrically-separate singles simply held together by a rubber block. Both types of triple sockets are shown in the next photograph along with a double.


The triple socket at the center of the above photograph allows up to 6 wires to be electrically connected to each other and it seems little reason more than that would be needed on a motorcycle. Consistent with this, whether or not they exist (perhaps for cars?), I can't remember having seen a larger connector that had internal connections between the individual sockets. These larger connector blocks exist because they can help with organizing the wiring, not for electrically connecting a large number of wires together. Anyway, visually inspect the sockets you use to be sure they make the connections you think they make, and it's always a good idea to check them with an ohmmeter no matter what. A 5 second test with your ohmmeter when you're doing the wiring could save time and frustration later when it "should" work, but doesn't.

Crimp Lucas-Type Bullet and Spade Connectors
I don't use bullet crimp connectors myself so I will update this section with posts by other people who do use them once they post information. However, excerpted from a relevant post on a different thread is:

Motorcycles used soldered 1/4" spade connectors (called Lucar) for components like coils and horns. These connectors are shown in the next image.



While I'm sure ones very similar in construction can be found, I use crimp connectors that also can be soldered after crimping, shown in a package in the next photograph along with their insulators.


These are sold as either 1/4" or 6.3 mm (i.e. 0.248").

Crimp Connectors
Although many aren't of use on motorcycles, crimp connectors come in a variety of designs and often are sold in assortments of sizes and shapes. Even an assortment of an appropriate design will contain many sizes and types that aren't useful so, as a result, it's easy to use up some of them while many others remain untouched for years. However, connectors also are sold in bags of specific types so you can easily restock once you determine which ones you find most useful.

As examples of assortments, uninsulated crimp connectors are in the box at the left of the front row in the following photograph, solderable brass Lucas-type bullet connectors are in a bag in the center, and crimp connectors with several types of insulation are in the other three boxes.



Although I don't recommend them as ideal, by far the most common crimp connectors people use on motorcycles are ones whose insulators are color coded for the size of wire, with yellow for 10-12 AWG, blue 14-16 AWG, and red 18-22 AWG. Note that when using replacement wire supplied by Sparks or British Wiring the 14/0.30 size is equivalent in diameter to ~17.6 AWG so the red is most appropriate. Having said that, there are manufacturing variations in these connectors, especially from unknown suppliers, so it's possible to find connectors whose ID is too small to fit over the wire. Unfortunately, bigger isn't always better since the strength of the crimp depends on having the right amount of distortion and if there is too much difference in size the connection won't be as strong as it should be.

Shop carefully because most Cu connectors are tinned which makes them look a lot like cheap Al, which are to be avoided. Connector with three types of insulation are common. These look similar on brief inspection as seen in the next photograph.



At the top of the photograph is vinyl, which is the least expensive but fairly brittle so can crack when crimped. Better is nylon, in the middle. These can be distinguished from each other because vinyl is opaque while nylon is semi-transparent. Most expensive, at the bottom, are aircraft/marine connectors with heat shrink insulators. As can be seen the insulation extends past where the wire will be crimped to form a "waterproof" seal at that end and, after heat shrinking, at the other end as well.

Although these are advertised as "waterproof," so might seem to be better for that reason, it's not clear to me that even perfect waterproof connections would last longer in practice on a motorcycle than other ones. It's not that "waterproof" is bad, it's just that the additional expense of these connectors may not result in any lifetime improvement in practice. Others may have different opinions on their use.

Non-Insulated Connectors:
Although most of this section has been about common insulated connectors, it's because that's what most people are used to using. However, there are good reasons to use non-insulated crimp (or soldered) connectors along with shrink tubing. After all, the wire itself provides insulation up to the connector, and the connector is bare metal, so there's no functional reason to have insulation attached to the connector. Integral insulators are useful in crowded electrical junction boxes in a home to keep bare wires from touching (because heat shrink is seldom if ever used), but that's typically not an issue with motorcycle wiring. Especially, when done carefully rather than by a homeowner or an apprentice electrician wiring a house as quickly as possible. I'll add more on this later.

Crimpers
If you use crimp connectors you must have the right crimper to produce a connection that will have high reliability. The crimper with the yellow handle in the next photograph is a common one sold in hardware stores. It is not appropriate for use with motorcycle wiring,

At the left is an S&G Tool Aid set containing nine dies, each of which is to be used with a specific type of connector. In addition to having a number of dies, the crimper in the set has a ratchet that doesn't release until the jaws have been compressed by the correct amount. No such control is present in the hardware store type. Examples of crimps made with both of these crimpers are shown a little further down in this post.

At the bottom of the next composite is a hardware-store crimper with three shapes ("dies") in its jaw, sized for the three common insulated connectors (yellow, blue, and red). At the top is a proper crimper for these connectors.


Note that not only is the die of the top crimper much deeper, it also has different shapes at the front and back to separately take care of the electrical connection and the strain relief. Although the rounded shape at the front is roughly the same as the hardware variety, its dimensions produces a crimp ~80% larger in area. Clearly, this makes for a better electrical connection as well as greater mechanical strength.

The shape of the die at the insulation end of the crimper (which isn't present on a hardware store crimper) provides strain relief in the connector. This is shown in the next photograph using 12 AWG wire in a yellow connectors for 10-12 AWG.



I chose these connectors for this illustration because although for 10-12 AWG the inlet on them is especially large to allow for thick insulation on 10 AWG wire. The connector on the left was crimped on the 12 AWG wire with the hardware crimper so only the portion at the far end, where it contacts the bare wire, is actually crimped. The wire isn't constrained beyond that and it can be seen that the metal inside the connector nearest us is serving no purpose. Obviously, the manufacturer wouldn't have put metal there if it wasn't to be used. On the right it can be seen how a proper crimper also crimps the metal nearest us around the insulation of the wire to provide strain relief.

The next photograph shows a different inexpensive crimper that is intended for connectors without insulators. It has "square=ish" dies at the right and "dimpled" dies at the left. Dies for this type of connector are included with the set shown above (again, though, providing a larger crimped area) but it's worth showing this one as a reminder that many crimpers are available. However, each is designed for a specific type of connector so even if you have one that seems to fit what you're using only the correct one will form a reliable connection.



Aesthetics of the Connectors
Clearly, it's essential that whatever connectors you decide to use perform as they should electrically and mechanically. But, if they have the wrong appearance they can mar the overall appearance of a motorcycle. From top to bottom in the following photo are: 1) original Lucas solder connector, 2) aftermarket solder connector, 3) aftermarket crimp connector with additional heat shrink tubing, 4) aircraft/marine crimp connector with integral heat shrink tubing, 5) hardware store crimp connector.


All of these (and others) can be made to function appropriately, but the choice does have an effect on the appearance of the motorcycle as well as on how people evaluate the craftsmanship that went into it.

[to be continued]

Heat Shrink Tubing
Heat shrink tubing between the connector and the wire provides strain relief, moisture protection, and additional mechanical strength. This type of tubing shrinks in diameter by ~2x, but little in length, when heat is applied. This tubing is available in in quantity in different colors and diameters or as pre-cut lengths in kits as shown in the next photograph.


Heat Gun
The heat needed to shrink tubing can come from a cigarette lighter, but a heat gun is more uniform with less chance that you will singe the tubing or wire insulation.



PVC Sleeving
Some wires should be in protective sleeving for abrasion resistance, or just to make the installation tidier, and this material is available in bulk in various diameters. As for sizes to have on hand, two 17AWG wires easily fit in 3/16" ID and four in 1/4" ID.



Split Sleeving
There might be times when you don't want to rewire an entire motorcycle but where some of the existing wiring needs to be protected from abrasion, or just gathered together for neatness. At times like these I use Techflex F6 'split', or 'wrap-around', sleeving. It can be seen from the inset at the left of the next photograph how this springy plastic coils over on itself making it expandable as well as capable of being slipped over wiring that is already in place.


At the right of the above photograph are the three sizes of this sleeving that I have found to cover all my motorcycle wiring needs, 1/4", 3/8" and 1/2". The sleeve at the far right shows how it slips over existing wires as well as how individual wires can be easily withdrawn from a multiple-wire bundle where they're needed.

Wire Ties
The next photograph shows a variety of wire ties.


At the top are two "twist ties" from a box of sandwich bags twisted together to double their length because the standard length is too short for many purposes. These are used to temporarily hold wiring in position until it is time to attach it permanently.

Next are cable ties, commonly called "zip ties," of lengths approximately 8", 6" and 4". Although I have longer and shorter lengths of these as well, I can't think of ever needing other than these three sizes when installing wiring. Unfortunately, there doesn't seem to be a standard way of labeling sizes of zip ties requiring some investigation before buying them. The one that is nearly 8" long is from a bag that calls them '7"', the next one is labeled '5-5/8" long; 1-3/8" bundle dia.", and the smallest '4"; 1/16"-7/8" bundle dia.'. Also, the quality of these varies, with poor quality ones being much more brittle than others. Some contain UV inhibitors to make them longer lasting when used outdoors. These are what I recommend. Unless you are aiming for originality, plastic zip ties are a good choice.

Next are two lengths of aftermarket soft metal ties of the type that was used on machines from the 1950s and earlier.

Finally is a rubber tie that was used through at least 1965 on some machines (e.g. my 1965 Matchless G80).

Electrical Tape
Avoid using no-name electrical tape because the adhesive won't last and it often will have turned into a sticky mess if you ever have to remove it. Although I recommend 3M brand ("Scotch") electrical tape they make at least a dozen different types so the brand alone doesn't tell you everything you need to know. At the top of the next photograph is 3M 'Super 33+' tape and below it '700'.


Both of these black tapes have the same width and thickness ("7 mil" = 0.007") so might seem to be the same, but the "Premium Grade" Super 33+ is vinyl and rated to function over the range 0-220 oF while the "Commercial Grade" 700 is PVC and is rated for 14-194 oF. Further, the adhesive on the Super 33+ is 50% stronger. Of course, it's also more expensive. The 3M Super 88 seems to have the same specifications as the Super 33+ but is thicker, at 8.5 mil, which makes it less suitable for all but special applications;

Also shown in the photograph is a roll of red 3M 35 tape that I carry in my motorcycle toolkit instead of black. Tape is in the kit for emergency repairs and red gives me a visual reminder later that it's a temporary repair that needs to be attended to. This tape also comes in other colors.

Dielectric Grease
I don't know who coined the name for this, since all greases are dielectrics, but it is formulated to have very low electrical conductivity rather than to be a good lubricant. What that means is you can smear it over connectors without fear that excess grease might bridge the space to another conductor and cause a small leakage current to flow between the two. That said, all you want is a very light coating on the surface since any excess that is squeezed out will just collect dirt. Since it's a grease the pressure between a connector and its mating socket pushes it out of the way to make direct metal-to-metal electrical contact while at the same time the grease forms a "seal" to protect the contact from moisture and oxidation. A tube with enough grease to do the connectors on a dozen bikes costs only a few dollars so it is cheap insurance against the possibility of long term corrosion even in moist environments.



Contact Cleaner
Contact cleaner can be invaluable for restoring good electrical performance of problematic switches. The one I use on my electronic instruments as well as on my motorcycle switches is Deoxit G100, which I learned is highly regarded by ham radio operators. This brand comes in three types for "normal" contacts (listed at the top of the can at the right of the next photograph) and three corresponding types for gold-plated contacts, one of which is the G100 in the can on the left. The other types might work as well on motorcycles, but since G100 works it's the one I always reach for.



[to be continued]

Electronic Instruments
Without electronic instruments you would be working blind. Luckily, electrons have been around a long time as have the necessary instruments, and they need not be expensive.

At the left of the top row is an analog meter that measures Volts, Ohms and current to 250 mA. If this were the only instrument you had when you needed to rewire a bike you would be fine. I bought this meter in 1969 and still use it (sometimes there's no substitute for the swing of an analog needle), illustrating the fact you don't have to spend a lot of money to buy a meter for use when rewiring a bike. The downsides of analog meters are they aren't as rugged as most digital meters nor as accurate, although the accuracy is more than sufficient for wiring a motorcycle.


Next in the top row is an Amprobe PM51A credit-card size digital multimeter (DMM, also commonly called a digital voltmeter, DVM) from the toolkit I carry on rides, that measures Volts and Ohms. A Sperry DM-2A is similar. Since 60% of breakdowns are electrical it pays to have one of these in your toolkit and know how to use it.

Next is an inexpensive Scope DVM632 DMM that I've also had for years, that measures Volts, Ohms and current to 200 mA. This is a 3-1/2 digit meter, which means it will have a maximum reading on any scale of a 1 followed by 3 digits (e.g. 19.99 Volts). The most sensitive resistance scale reads to 199.9 Ohms, i.e. to 0.1 Ohms. Such resolution and sensitivity is completely adequate when wiring a motorcycle. On this unit, as on some of the others I own, is an audible buzzer that can be activated on the Ohms scale that signals when the resistance is small, i.e. a short. This can be very useful when searching for a short in a difficult location where you can't easily see the meter as you probe around.

As an aside, most people don't give any thought to absolute accuracy of a meter, assuming that whatever a meter displays is accurate. I have the instruments to check the voltage calibration to an absolute accuracy of 2 ppm (resistance to 0.01%) and found that of the eight non-credit-card DVMs I have that are as old as 30 years only one was out of spec, by only 1.4% (which I recalibrated). Anyway, this shows that while it shouldn't be assumed that an old DVM is accurate, chances are it is.

Stepping up in price is the rugged Fluke 79 DMM at the left of the front row. It also measures Volts and Ohms like the previous ones mentioned, but current to 10 A. However, you don't have to spend this kind of money to have something appropriate for rewiring a motorcycle.

Finally, a Wavetek LCR55 (also sold as Amprobe LCR55) that measures resistance, inductance and capacitance, but not voltage. This wouldn't be my first recommendation, but its most sensitive scale allows reading resistances down to 0.01 Ohms which can be very useful. Also, its inductance scale is equally useful when timing a magneto or an ET ignition system because the inductance changes by ~10x when the points open whereas the resistance changes by only ~1/2 Ohm.

Also shown in this photo are a selection of probes for these meters. Often it is useful to have a pointed probe at one end and an alligator clip or other type of "grabbing" tip at the other. Some probes provide both in the form of alligator tips that can be unscrewed to reveal sharp probes.

A more specialized instrument that isn't essential, but that can be very useful when wiring, is a clamp-on ammeter with a DC scale as shown in the next photograph. Inexpensive versions of these only work on AC which isn't useful for us.



On the 40 Amp scale the final digit displays 0.01 Amps, i.e. 10 milliamps. Ammeters more sensitive than this are part of some of the DMMs shown above, but all of them require breaking into the wire to insert the meter in series.

If you want to check if a certain component such as a Zener diode is allowing current to flow when it shouldn't, or if a switch is malfunctioning and not turning 'off', simply clamp this around the wire leading to/from the component. If a current just under its level of detection is flowing (9 mA) it would take 40 days to drain a typical motorcycle battery (~9 Amp-hr) so using it is a very quick way to check for issues large enough to be a significant problem. Also, leads can be attached to use it as a 3-1/2 digit voltmeter and ohmmeter as well so it is a (more expensive) alternative to a standard DMM.

[to be continued]

:bigt

Note: Yesterday I added new content on Lucas bullet connectors to an earlier post. Unlike most threads that proceed in chronological order I will be organizing at least the earlier sections of this one according to content to make finding material much easier. This means earlier posts might change significantly. It's too much trouble to point out specific additions/changes so the only way to know is to skim through the earlier posts. As an example of changes, at some point I'll probably delete this 'note'.

Wiring Diagrams
The next two images show how much the wiring of British motorcycles increased in complexity between the late 1940s and early 1970s,





While the second diagram has many more components and wires than the first, the wiring principles are the same. It's just that rewiring a c1972 motorcycle will take longer than one from c1952 (or c1932 or...).

Since not everyone may be familiar with reading diagrams like these it's worthwhile to spend some time describing relevant features using the simpler of the two.



Although it isn't apparent from the above diagram everything highlighted in red is inside the headlamp shell. Note is that although the headlamp shell occupies only a small part of the total motorcycle, the wiring inside it takes up half the wiring diagram. This illustrates that you can't infer details of the physical layout from a wiring diagram.

Starting at the top left, the blue arrow pointing at the Parking Bulb shows only one wire connected to it. Without exception every component must have a minimum of two electrical connections so something seems to be amiss. No matter what, current from one terminal of the battery has to enter a component through one connection and eventually return to the other terminal of the battery through a second connection.

What is shown in the diagram is that the Red & Black wire is attached to the bulb. Although, since the internal connections of the switch aren't shown on this diagram, it's not obvious that this wire makes its way back to the battery, it does (via the purple wire to the ammeter and from there to the battery via the brown wire). However, what isn't shown is that the Red & Black wire connects to one side of the bulb's filament and that the other side of the filament connects to the base of the bulb which is in electrical contact with the shell of the headlamp housing. The housing in turn is earthed/grounded to the frame as is the battery. Thus, the Red & Black wire provides one of the two necessary electrical connections to the bulb from the battery and the frame provides the other.

The headlamp shell on most bikes is earthed to the frame through the steering bearings, which isn't the ideal way of providing a good electrical connection. However, while proper earthing of components like the headlamp and tail lamp housings is important and will be addressed again in a later post, for now the point to make note of is that that sometimes earth connections on wiring diagrams are implied rather than explicitly drawn. This is the case for the earth connection of all bulbs in this wiring diagram.

The arrow at the right, top points to the electrical symbol for an "earth" (or "ground") connection, which is the frame of the motorcycle.

To digress for a paragraph, especially in the case of an appliance powered by the mains (e.g. 110 V or 220 V), portions of the internal circuits typically might operate at different voltages but often they will share a common return path that also might be connected to the metallic appliance housing. That path is commonly referred to as the "chassis earth," or just the "earth." Typically the internal "chassis earth" is connected to the actual Earth through a third connection, although this is needed for safety not for functioning of the appliance. This is the third, larger, connector on household plugs. Exceptions are "double insulated" small appliances that only need two connections on the plug because internal insulation keeps the mains voltage from ever reaching the outer housing. Since internal failures of most appliances could result in the mains voltage being present where it could cause injury there has been a connection to the actual Earth on all new household wiring installed in over a half-century. However, no current will flow through the Earth connection if everything is functioning as it should, and ground fault interrupters (GFI) typically are incorporated in bathroom and kitchen circuits to break the power connection if even a tiny current flow in the Earth wire is detected.

Anyway, although historically "earth" actually did mean a low resistance electrical connection to the dirt/ground of the Earth that was made for safety reasons it has been a long time since that terminology was strictly observed. What's relevant for our purposes is that in Lucas terminology "earth" means the motorcycle frame. This is shown in the following portion of a diagram from a Lucas manual.


This diagram is a bit odd in that, if taken literally, it shows that the frame is earth but it also shows a wire running to an earth symbol as if that wire were a physically separate connection to something other than the frame. However, this is just the result of the draftsman struggling to include something that looks like part of a frame as well as the symbol for earth in the same diagram.

Depending on the specific motorcycle the frame can be "positive earth" (i.e. directly connected to the '+' terminal of the battery) or "negative earth" (connected to the '-' terminal). The wiring diagram has to be consulted to know which wiring convention was used, and compared with the current wiring to be sure someone hasn't altered it.

Although the next arrow in the above diagram shows a horizontal wire crossing three vertical ones they do not make electrical connections with each other. Diagrams are drawn this way because of space considerations. While the these wires may be touching, the resistance between the Cu wires inside the insulation of the wires is many megOhms which means the leakage current through the insulation would take millions of hours to drain a battery. Wherever an electrical connection between wires is made it will be explicitly shown (such as where two wires connect at the Horn).

An arrow further down to the left of the wiring diagram shows the '+' terminal of the battery is connected to earth, i.e. to the frame, so this is a "positive earth" system as are most (but not all) British motorcycles. Important to note is the earth connection on this diagram is made via a Black wire. Often the first (and only?) thing many people learn about electrical wiring is red means positive and black means negative. As this diagram shows, this is not necessarily true. By the 1960s the Lucas convention changed to using Red for this connection so it is important to consult the specific diagram for your year and model motorcycle in order to know what colors were used by the factory for various wires.

On the subject of color conventions, in the first 12 years after the introduction of the stator/rotor alternator the three wires from it changed color four times:

Light Green__Light Green___Green/White___White/Green
Mid Green___Green/Yellow__Green/Yellow__Green/Yellow
Dark Green__Dark Green____Green/Black___Green/Black

Finding wires with three distinct shades of green is not easy which makes it difficult to stick with the original wiring convention of early machines. Another example is the diagram for my BB Gold Star shows a maroon wire for the tail light and I have yet to find a source for wire in that color. As these examples show, you may have to make accommodations even if you would prefer to just follow the original wiring scheme for simplicity.

The final arrow on the above figure points to the symbol for the female snap connector that is used to connect two wires together via bullet connectors on the ends of those wires (described in a previous post). Note that four connectors are shown that seem to be adjacent to each other. On the actual motorcycle two of those connectors would be very near the tail lamp assembly to allow it to be removed, but the other two would be much further forward on the motorcycle. This again illustrates that any wiring diagram only roughly corresponds to the physical layout on the motorcycle itself.

[to be continued]

Hi,


Moral? Stuff on Ebay is cheap for many reasons, "cheap" and "best" are not interchangeable in the English language.


Ime, apart from "triples", no others are available in both "electrically connected with each other" and "electrically-separate singles simply held together by a rubber block" types; "doubles" and "quadruples" are always the first type only, "quintuples" are always the second type only.


I use two "quadruples" when constructing the "earth" wires' network and either a "triple" 'common' or a "quadruple" when constructing the White wires' network, depending on how many individual components need to be on with the ignition switch.


Have you ever actually seen any like this? Reason I ask is I never have, neither on old harnesses or new loose terminals.


Uh-uh ...

... As I say, never seen anything like the ones in the Lucas pictures.

... The ones in your photograph are for housings - the piece hanging down locks the terminal in place in the housing unless pushed up by the correct tool ... or a small screwdriver ... Owners of old Britbikes won't encounter them unless they have either a very late Meriden twin - Lucas supplied at least some black handlebar switch clusters and corresponding harnesses with 'block' connectors - or a Japanese bike.

... I would like to see one of these terminals with the wire soldered similar to the Lucas pictures; afaict from the similar terminals I have, wire through the slot will prevent proper engagement of a male terminal.

... I've some Lucas-branded female terminals from the 1980's; they have the 'ramp' to engage a male terminal, as drawn in the bottom two Lucas pictures, but there is no way they can be soldered as in the pictures.

... Finally here, risking telling you something you know already, the insulators in your picture are for when two wires are attached to one tab terminal; when only one wire is attached, there's a different insulator, that fits more-closely around the wire.


Get Thee Behind Me, Satan!

I'd go further. In the second (or maybe you're reading this in the third!) decade of the 21st century, it's neither difficult nor expensive for anyone to get the non-insulated connectors. If someone building a harness is too lazy to do that, what else has he/she been lazy about? It might be possible to produce a perfect harness with these connectors; unfortunately, as legions of bodgers have preceded for decades, it's hardly surprising that people like me will condemn any harness with more than a few of the very specialised ones?


Not from the late 1950's onwards, it isn't. Through the 1960's more and more components on the vast majority of Britbikes are connected to a network of Red wires connected to battery +ve, rather than relying on their mounting alone for a return.

Lucas becomes irritatingly-inconsistent from the 1970's - rear lamp finally gets a Red wire from about mid-'71, but by then they're supplying indicators that return through their mounting only. There are also some harnesses where the washer to fit under one of the head bolts/studs (Lucas's version of single-point ground) isn't connected to battery +ve - the current must return by sundry cycle parts connections to the wire between rectifier and battery +ve.


As I say, this becomes less-true as the 1960's progress; certainly, in some years, Triumph and BSA actually differentiated between Red-wire and cycle-parts "earths" in/on their diagrams.

Also, ime it's unwise to draw too many conclusions from the detail (or lack of) in individual makers' wiring diagrams; afaict Lucas wiring diagrams were frequently redrawn by makers, with consequent additional mistakes and other omissions.

Hth.

Regards,

Stuart, I am fairly sure I saw those Lucas soldered terminals on the original harness from TR6Rays 64 TR6.

Rod

Stuart,

Thank you for your post. Taking your points in order:

1. Yes, items from ebay can be inferior. But, it also can be an excellent source of hard to find items. Although caveat emptor applies, my intent with the information in this thread is to make better informed emptors.

2. As for whether snap connector blocks larger than three can be found with internal connections, even limiting discussion to the 40+ years of post-WWII production, it's hard to make definitive statements about certain components like these. That's why I wrote "Anyway, visually inspect the sockets you use to be sure they make the connections you think they make...". Also, let's not forget that Lucas supplied the car world as well and there has been ample opportunity for cross-species intermixing of components that might never have been used on motorcycles, adding another factor to all of this.

3. Lucar connectors like the ones shown in the diagram are found on ET coils and perhaps other places as well. Also, maybe I should emphasize that I've only shown a sampling of the various types of connectors I have. The point is, many variations of connectors are available so one has to look carefully to make sure ones that look roughly the same actually are suitable for the required application.

4. As for insulated "hardware store" crimp-on connectors, although I wrote that I don't recommend using them, just about every wiring job I've seen does. Because of this, to write "don't use them" and then move on to the next topic would be like teaching a sex education class based on abstinence-only. That might be a goal in the abstract, but in a practical sense it's futile. Since people are going to do it, it's best to know the proper tools and supplies to keep them out of trouble when they do what they've been advised not to do.

5. I tried to make the point using just two wiring diagrams that things got significantly more complex with time. However, it's impossible to cover every variation of earthing, or anything else, in detail over the 40+ years so I'm focusing on principles, tools, and supplies that apply in general. To emphasize the point again, the wiring diagram for a specific machine (complete with hidden assumptions, like some earth connections) has to be consulted. Also, as you pointed out, just as in other places in shop manuals, mistakes can be found in some wiring diagrams.

I hope I've addressed all of your points with the above explanations.

Hi Nick,


You are misreading my contribution. From MM's first post:-


Having had a bit of experience in this, I'm merely contributing an alternative viewpoint to some statements; a reader is free to accept or discount whichever.

That's specifically why I posted, for example, "I haven't seen them" to the drawn Lucar female terminals, rather than extrapolating that to "They don't exist".

Likewise, Lucas might well have supplied particular car or truck makers with snap connectors able to take far more wires than the ones now generally available. I'm just saying I haven't seen them, but then I haven't rewired every model of British vehicle from the last sixty-odd years.

Otoh, like BSA, the car and truck makers paid Lucas as little as possible for their harnesses too. So, for Lucas to have made a profit too suggests that they're likely to have built all harnesses from as few similar components as possible?

Hth.

Regards,

+1. This is exactly how I read Stuart's contribution. That's why my reply wasn't a "counter-argument," because there wasn't an argument in the first place, but rather a clarification.

Stuart is clearly quite experienced with British wiring, but no two people are going to agree on all points. Where we do end up disagreeing it's possible it will be because one of us is right and the other wrong, but more likely it will be because our own experiences have lead us to different approaches. Bringing up disagreements and alternative approaches isn't a "s--tfight," which would be pointless, but the best possible way to describe and clarify choices people will have to make when wiring their own motorcycles.

Hi,


Mmmm ... imho, the advice here isn't consistent with some of your earlier posts:-

. I quoted a sentence from your first post to Nick above.

. Your earlier back-and-forth with "needing".


You've posted already that "trailer cable", "Lamp cord, household wiring, power cords from old computers" could be "suitable" but are not "professional". Given that wire can be bought easily in several sizes with almost all the correct insulation colours, almost all the correct terminals and insulators can be bought just as easily, why is advising that the revoltingly-coloured "insulated 'hardware store' crimp-on connectors" also could be just "suitable" but they are also not "professional" "like teaching a sex education class based on abstinence-only"?

. Given the posts and threads over a long period about the correct bearings and piston rings to use in an engine rebuild, would you consider an engine rebuild that uses bearings and piston rings that have been advised against to be "professional"?

. Under "Introduction" in your first post, you wrote, "there are three approaches to rewiring an old motorcycles: 1) buy a reproduction wiring loom"; would a "reproduction wiring loom" made with revoltingly-coloured "insulated 'hardware store' crimp-on connectors" be "professional" and would anyone pay a similar amount to one made with correct-looking terminals and insulators?

Imho, simply detailing best practice will mean a long thread with much information for a reader to appreciate; lengthen that thread to include advice "to keep them out of trouble when they do what they've been advised not to do" and you risk confusing a reader with what is best practice. Some people are always going to do things despite being advised not to; if you feel you must include advice "to keep them out of trouble", why not as a separate topic, "like converting from 6V to 12V, changing to electronic ignition, etc."?


I appreciate that. But the last sentence in my previous post was agreeing with your "it's impossible to cover every variation of earthing"; my point is it's unwise to infer any particular"earthing" from a wiring diagram; imho, it's best to understand best practice and use that, irrespective of what the original maker(s) did or didn't to save a few pennies.

Hth.

Regards,

Because, as I already explained, no matter what I write about hardware store insulated connectors, my expectation is that sometimes people will use them anyway. So, rather than teaching abstinence-only, since they're going to do it, they need to know how to do it properly.

Hey, I'm doing the best that I can. Although I try for consistency, anyone who holds me to that standard in Forum threads is bound to be disappointed from time to time.

Other approaches to the topic than the one I'm taking certainly would have been possible. But, I'm happy with my approach, and am not interested in spending time to defend my choice rather than create additional content. So, the question is, is the information I've provided thus far so inconsistent or misinformed that it would be better to delete the thread to avoid misleading people, or can others make positive contributions to improve and expand the content?