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1970 Bonnie Wiring Harness Question
#719524 12/20/17 9:04 pm
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I should really replace the wiring harness on my '70 Bonnie as it is not original and has had some repairs over the years. Would the original harness for this bike have been cloth-covered or taped? The one on the bike now is taped.

Bruce


1937 Ariel Red Hunter 500
1970 Triumph Bonneville

Making the scene with the gasoline
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Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719553 12/21/17 12:41 am
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1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719556 12/21/17 12:58 am
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Thanks - I'm sure the harnesses are good quality but this doesn't really answer my question. What was standard equipment for a 1970 T120R Bonneville - braided cloth or taped/plastic covered wiring?

Bruce


1937 Ariel Red Hunter 500
1970 Triumph Bonneville

Making the scene with the gasoline
Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719557 12/21/17 1:24 am
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I have tried to fix harnesses before and sometimes its just not worth the hassle. I stock new Lucas harnesses which can be found in the link (wiring diagram included)


https://www.classicbritishspares.co...-54955256-54957095-t100-t120-tr6-1969-70


[Linked Image from live.staticflickr.com]
Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719564 12/21/17 2:38 am
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If you scroll down you will see both a cloth covered and a taped harness. My 68 is cloth. I think it looks so much nicer than tape, even though I am the only person that sees it. Till some one can answer the question about a 70 you will have to wait. At least you know where to buy one. .


1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719580 12/21/17 7:32 am
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Hi Bruce,

Originally Posted by Bruce Martin
Would the original harness for this bike have been cloth-covered or taped?

The one on my '70 T150 is cloth-covered. The very long-time and knowledgeable Triumph/BSA guy who imported, rebuilt and sold the bike to me said he used a nos harness.

Hth.

Regards,

Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719588 12/21/17 10:22 am
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Stuart, many vendors carry harnesses these days, is there anyone in particular you like to recommend?
I've bought a Lucas branded harness from Feked, it does look OK to me, but then I'm definitely not savvy enough to tell for sure.

Any input appreciated.

Re: 1970 Bonnie Wiring Harness Question
Stein Roger #719603 12/21/17 2:30 pm
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Hi SR,

Originally Posted by Stein Roger
many vendors carry harnesses these days, is there anyone in particular you like to recommend?

Thank you for your confidence, but I regret not. frown

With the exception of that T150 harness, my experience of off-the-shelf harnesses has been bad. frown For what they contain, even the best-quality modern ones are expensive, and many available are certainly not best-quality. frown Also, with the possible exception of requests to British Wiring in the US, all off-the-shelf harnesses are still standard and so require modifying for now-common components like reg./rec., electronic ignition, etc. So, if you have to buy the tools and parts to modify an off-the-shelf harness, you might as well buy the few more parts to build your own guaranteed high-quality one? smile

Originally Posted by Stein Roger
I've bought a Lucas branded harness from Feked, it does look OK to me, but then I'm definitely not savvy enough to tell for sure.

As I say, my experience of off-the-shelf harnesses has been bad ... cool Also, "Lucas" (as in "Wassell") help retailers with images and text to advertise the parts on websites; I am not sure that a retailer like Feked has the experience or judgement to reject any 'Wassell Lucas' component on quality grounds ... cool

Not an exhaustive list, but some indications of "quality":-

. All wire insulation colours and combinations correct.

. In pre-'71 harnesses, Lucas supplied thicker wire for the Red to battery +ve, White from the ignition switch, Brown/Blue and Brown/White wires. It will not be obvious if the builder has used modern automotive thinwall wire, which has the desirable greater number of conductor strands inside thinner insulation; you could only check this by cutting off a terminal, stripping off a short length of insulation and counting the strands. frown What is definitely poor quality is using the same wire thickness (particularly number of conductor strands) for all wires. frown

. If a '71-on harness has the thicker wires (except the Brown/White), that would be a definite 'quality' plus, as the maker has though about it, rather than just slavishly replicating 'original Lucas' cost-cutting.

. On all harnesses, bullet terminals should look similar to, and spade terminals should look the same as, 'original Lucas' ones. Bullets should be insulated with snap connectors, spade terminals should be insulated with slide-on, slide-off soft translucent plastic insulators.

Hope this helps.

Regards,

Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719605 12/21/17 2:40 pm
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The significant one is to follow the red wire wink

http://transgarp.dyndns.org/motorcycle/2000/20170914/27.JPG

Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719613 12/21/17 3:58 pm
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Awhile back I helped a friend replace a 1970 T120R harness, and was noting the same shortcomings as usual (for me)- the wires were smaller, and the wire ends at the toggle switch were straight spades, not the angled (flag type) as the original (Cloth covering looked great).Things got hard to fit at the switch in the headlight bucket, but we thought we had it. all was well when tested with the light lens wired but laying on the front fender.When time came to test with the headlight installed,soon after switching smoke started pouring out- melted the white wire insulation at the ignition switch and also the fuseholder, but never blew the fuse. Oddly I don't remember what amperage the supplied fuse was. The cause is the strangest part, turned out a wire at the headlight switch had a "stalagtite", or sharp pointed bit of solder that actually poked through the clear insulation on the spade when the headlight reflector was installed. I don't know who made it, came in a plastic bag with no label, just a number written in marker- I think it had 2 letters and 3 numbers, like "MC-123", but don't remember that either. I used several of the same brand on my own bikes, but never had anything like this happen.

As for original question- I've never seen a taped loom on a stock triumph, and I've seen lots, but all pre-oif.

Also worth mentioning, This was second '70 model harness I've replaced, and both originals had turn signal wiring in the loom, with the ends cut short. Same colors as later indicators. Anyone else aware of this?

Last edited by tiumphdave; 12/21/17 4:04 pm.
Re: 1970 Bonnie Wiring Harness Question
tiumphdave #719624 12/21/17 5:18 pm
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Hi,

Originally Posted by tiumphdave
noting the same shortcomings as usual (for me)- the wires were smaller,

I wouldn't call this a 'shortcoming' always. Even before '71, Lucas used wire consisting of 14 strands, each 32SWG, rated for 7.5 Amps to and from individual components. Otoh, there is a standard metric wire consisting of 9 strands, each slightly larger 0.3 mm. o.d., rated for 5.5 Amps; 5.5A is more than adequate for most individual components.

Or a harness maker might have used 32/0.20 thinwall. This has a slightly larger conductor cross-section than 14 32SWG strands but, thanks to its insulation properties, is rated for 16.5A. I've only ever used it once, rewiring someone's bike with wire he'd bought; for some reason, it was a 'mare trying to get bullet terminals to stay on, crazy so I never used it again. If that's been solved, good-quality harness. :bigt

Originally Posted by tiumphdave
cause is the strangest part, turned out a wire at the headlight switch had a "stalagtite", or sharp pointed bit of solder that actually poked through the clear insulation on the spade when the headlight reflector was installed.

Otoh, maybe I should add 'soldered terminals' to my list of 'quality' fails? smile Ime, it's a lot harder to solder well than it is to crimp well - especially with correct (easily-available) tools and terminals. So why would the maker of a good-quality harness risk an unnecessary screw-up like that? confused

Originally Posted by tiumphdave
I've never seen a taped loom on a stock triumph, and I've seen lots, but all pre-oif.

Taped is standard in the 1970's - possibly '71-on?

Originally Posted by tiumphdave
This was second '70 model harness I've replaced, and both originals had turn signal wiring in the loom, with the ends cut short. Same colors as later indicators. Anyone else aware of this?

Yep, seems to be standard at least in '70. However, it's only the Green/Red and Green/White wires; the Light Green/Brown wire from relay to handlebar switch isn't present, nor is the White wire to the relay. '70 rear grabrail also has the mounting holes for turn signals.

But I don't know why the bikes didn't get turn signals ... frown

Hth.

Regards,

Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719625 12/21/17 5:21 pm
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Its a job to tell quality by looking. Earlier this year I rewired a mates 50's Wolseley, the loom looked great, but when I came to test stuff, had a strange fault, turned out that a green wire, of which there were several in the same area, but all with different connectors, went into the loom and straight back out, instead of back to the voltage regulator as it should have. Also was a wire completely missing, which by sods law was meant to go to the reversing light, via the roof lining, of course I didnt find it was missing till I had replaced the lining!

[Linked Image]



Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719639 12/21/17 6:29 pm
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Thanks Stuart,

Back in 1980 I was forced to re-wire the entire system on my 71 Bonneville, and did it all myself using quality wiring and connectors bought at a local gas station! Non-standard colors, but enough different colors to make it work, relays too, those were the days!
These days they hardly carry fuses or bulbs, but they can serve you a dinner!
Built a few other looms too back then, but after that I haven't really needed to, until the arrival of the 1954 6T I've just re-commissioned.
As I'm doing an increasing amount of wiring repairs these days, it seems I need to step up the game and A) learn the trade, and B) buy some kit from Vehicle Wiring Products or whoever.

I must have done something right though, the one I did in 80' still worked fine when I had the bike in for service 33 years later.

Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719646 12/21/17 7:29 pm
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I have rewired a few British bikes. I generally use the stock wiring diagram, and stock wire colors, but modified to fit any changes I have made to the various components and incorporating extra ground wires for the headlight and the tail light. For wire, I buy old British harnesses at swap meets. They are usually available for less than $10. I use original type connectors from British Wiring. I have the Lucas bullet hexagonal crimp connector. It was expensive, but one of the best investments I ever made. The bullets go on nicely, stay on and look nice too. I use a ratcheting crimp connector for any butt connections to extend wires. I figure that at some point in the future, it is going to be a whole lot easier if the wires match the color code on the wiring diagram.
I rewired and old little Italian bike not too long ago. The nice part is that the Italians used basic colors, red, white, blue, green, black, white and yellow. So wire was available at the auto parts store. The weird part was the philosophy. Instead of wiring from component to component like a British bike, they have a complex and very fiddley switch in the headlight, and everything runs to and from the switch. Was quite different to my experience and took me awhile to grasp (diagram in Italian didn't help either).

Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719663 12/21/17 10:37 pm
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Where can one buy one of those Lucas connector tools?

Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719664 12/21/17 10:47 pm
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Re: 1970 Bonnie Wiring Harness Question
Bruce Martin #719665 12/21/17 10:57 pm
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1968 T120R
1972 T120RV
Any advice given is without a warranty expressed or implied.
Re: 1970 Bonnie Wiring Harness Question
tiumphdave #719916 12/24/17 2:48 pm
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Originally Posted by tiumphdave


As for original question- I've never seen a taped loom on a stock triumph, and I've seen lots, but all pre-oif.

Also worth mentioning, This was second '70 model harness I've replaced, and both originals had turn signal wiring in the loom, with the ends cut short. Same colors as later indicators. Anyone else aware of this?


I have restored a few very original 1967 T120s . All had taped wiring harnesses. I have only seen these on 1967 T120R's . I bought two NOS Lucas wiring harnesses and they were taped not cloth. They came in a Lucas box with a 1967 date on the box. A very low mileage 1967 TR6C came in a while back and it had cloth harness.
1970 T120 were cloth covered

Last edited by RPM; 12/24/17 3:29 pm.
Re: 1970 Bonnie Wiring Harness Question
RPM #719923 12/24/17 4:28 pm
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Hi,

Originally Posted by Stein Roger
Back in 1980 I was forced to re-wire the entire system on my 71 Bonneville, and did it all myself using quality wiring and connectors bought at a local gas station!
I must have done something right though, the one I did in 80' still worked fine when I had the bike in for service 33 years later.

Mmmm ... I did my first rewire only a couple of years later, my first T160 over the '82/'83 winter; that is also still going strong. At the time, I used standard wire colours mainly because I thought it was all going to go horribly wrong, and I would need the services of professional auto-electrician. Since then, wire with standard Lucas colours has remained easy to buy and, having been asked to sort out wiring problems on other people's bikes, non-standard colours is a definite eek

Originally Posted by Stein Roger
buy some kit from Vehicle Wiring Products or whoever.

As well as VWP, I have also used Autosparks for several decades; when making up an order for a bike, each is always cheaper than the other for some components ...

Originally Posted by edunham
rewired and old little Italian bike
the philosophy. Instead of wiring from component to component like a British bike, they have a complex and very fiddley switch in the headlight, and everything runs to and from the switch.

To a certain extent, Britbikes up to the early 1960's are like this, with (usually) a Lucas PRS8 controlling everything. Thereafter, the functions were split between separate Ignition and Lighting switches and, when the Zener diode removed the need for alternator charge regulation through the switches, they were simplified again to modified car switches. It was only the Japanese putting more functions on handlebar switches that made later British ones more complicated again. smile

Originally Posted by RPM
I have restored a few very original 1967 T120s . All had taped wiring harnesses. I have only seen these on 1967 T120R's

Interesting to know, thanks for that.

Hth.

Regards,


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