Britbike forum Forums Thread Like Summary - DIY wire harness

This is my next little project. If anyone is considering the same here is what I have found appealing so far in the aviation industry. My only concern is the gauge of wire and technical difficulties of being too big. I don't know for sure but I think this is 22 gauge. What happens or could happen if the gauge is too big? I love the idea of having text on the wire rather than color codes!!! The ability to have text ...High Beam, Low Beam, Brake Light, Running Light...ect. This makes trouble shooting much easier. We can now laugh at color codes, eh? I hope to find smaller gauges.

https://www.aircraftspruce.com/catalog/elpages/laserwire.php?clickkey=6369

Hi Splash,
The wiring on these bikes is already as minimal as it can be, if you want all the functions to work.

Lucas didn’t include any superfluous, deletable wires, with the only possible exception being if you don’t have indicators fitted.

You will never achieve your dream of reducing the system to just a handful of wires.

With all respect, I don’t think you have the understanding of the original system to confidently improve upon it.

If your existing loom is a dreadful mess, I think you’d be better getting a decent new loom, and working from there.

Building from scratch isn’t difficult, but from your questions so far I don’t think you are at the level of understanding to do it confidently. It would require detailed guidance at many steps of the way, Stuart may have that sort of patience.

If this task is attempted without the proper cables, connectors, tools and competence, you could end up worse than where you are now.

Sorry to be a downer, but a realist.

I just remade the harness on my Trident. I used common 16ga red and white wire for the common and switched hot leads. Everything else came from British wiring, 28 strand for the main lead from battery to switch, 14 strand for everything else (sometimes doubled for certain high current devices.)
I prefer Japanese connectors, better strain relief, smaller, and the proper crimper doesn't cost a fortune.
A dressmaker's tape can be used to estimate the length of wires, or use existing wires. I always cut an inch or two long until I actually assemble on the bike.

I’ve had 30 years in the motor trade and electrical has always been my weak point. I have however re wired both my 60’s Triumphs, one with an off the shelf loom and the other from scratch using correct colours. Neither task was half as confusing as the apparent logic behind this or the previous Tri Spark thread.

Yeah , the original wiring only lasted 50 years ,
the old thing deserves a Little Tenderness and not your bad attitude .

Wiring is one of the easiest projects ...No precision measurements required, mistakes don't require engine or gearbox disassembly, no oily messes.It seems even experienced mechanics have anxiety over stands of wire covered by thermoplastic..
Get a grip, it's fun to do...

Having assembled a custom loom for a pre-unit with all the toys I found trouble taken here is worth the effort. I calculated the optimum cable amp / mm/sq for each cable, used thin wall insulation, and that's important, because by the time they are all bundled, using std wall insulation can make for an unwieldy loom.

You should also use a high purity copper, 16.5 amp / 1mm/sq - 25 amp 2mm/sq normally stated if a quality supplier, multi stranded cable. Any that cross the steering boundary, think about increasing (using thinner) strands but same CSA to make it more flexible. I do recall having to deviate from the colour codes to achieve extra multi strands. Connections are just as important. For the most, I used Deutsh connectors, a bit more expensive but water / vibration proof and low resistance, soldered connection rather than swaged. This was several years ago, and I've had no problems with corrosion, ingress or poor connection. Having reliable connectors is very hand if you want to split the harness at strategic points, like inside headlamp and before steering, indicators etc.

Like already said, planning is key, if your using a std diagram, add all those other bits you may need like integrated voltage/regulator, indicator's & flasher unit, charging point etc on a diagram that suits your needs. I'd put some pics on, but don't understand the linking requirement.

This has been a very helpful conversation.

Although I have re-wired a few bikes, wiring has always been my weak point.
I can do it, but I'm not proud of it.

I've had to work on too darn may bikes like that!

I had built a cafe racer from a 84 Moto Guzzi. Hand made new wiring harnesses from primarily black wires with a few red and blue. The bike has a lot more wiring than a Brit bike plus I added relays for lighting...So Pete Suchawreck on this site buys the bike ...After a time the bike has a small electrial issue..I go over to Pete's place to have a look.. He says, how can you tell what wire goes where? I go right to the problem, just a loose female connector....
All them colors are just a distraction....

Industrial equipment that I have across certainly has wires of all the same color with numbers at each end of the length of wire--often in the past little numbered collars which lightly crimp onto the wire.
This works for static equipment.
However on a bike often the problem is chafing or wires being clamped away from the ends of the wire-- chafing around the steering head etc.
In these situations it is very helpful to have colored wires--in that the colored wires are colored for all the length of the wire--so if you have a problem mid length of the wire you can tell from the color which wire it is.
If you are fixated on numbering the wires then number the correctly colored wires---this should suit everybody!

Splash, believe it or not but I can sympathise. I suffer from a similar sensory dyslexia ( Thats a good description! ). Opening up the wiring diagram page in the manual sends my brain in to an odd melt down and the page turns into one big blur, same thing with a bundle of wires, would not make any odds if they were numbered or coloured in my case. What I found helpful ( You may not ) was to cover all but the circuit I wanted to see and try to look past the straight line look of the diagram. Once I know that the tail and park lamps are wired in brown with a green trace I translate that to the Lucas code N/G and only follow that line on the diagram to see what components that wire picks up on it's travels. Worked for me.

Your analogy with the aviation industry is interesting but your comparing apples and oranges. An aircraft mechanic is not typically expected to perform side of the road repairs. The day your stood by the side of the road and have reached your fault finding limits, having the bike wired in a standardised manner will mean the guy you end up paying to sort the issue will spend less time trying to get into your head to understand what you have done and more time actually fixing it.

A few are unecessary but the biggest problem is previous hacks who think cutting wires and poorly done crimps will fix it
No need to look,the wires talk to me...the engine talks to me..The hiss of the tires on the road, the wirr of the drive chain, the gear howl etc, lots of conversations....

Hi Splash, Use 1973 wire diagram. Ignore kill switch & turn signals.

You’ll find Triumuph didn’t waste any connectors either.


Tiger Cub had very good suggestion. Make a drawing of bike with components. Then draw in wires.
Don

Hi Splash, You pretty much covered it.

The only thing you are eliminating is the few items you listed. Wires to ammeter. Wire to zener up front.

The electronic rec/reg has same wires as the old disc rectifier did. If you run ground wire to battery positive & charge wire to battery negative you are actually adding more wires.

So end of day you will basically be replicating later factory harness in your own way. But no turn signals.

For coil power you will use 2 coils with points. Power wire will come from ignition switch & go to one coil, a short jumper will power the other coil. You'll have the 2 wires to the points as before as well.

Tri Spark you'll save the jumper wire between coils. Then add a different jumper wire between coils. Then a ground wire to one coil. The points wires will be repurposed but still go to points case. So you save nothing. You discard condensers with Trispark.

If I was you, I'd keep the Trispark. In the long run you'll not have to service points. Once you set Trispark timing it stays set there after until you remove the timing cover for some reason.

You could mount your new rec/reg same place as your Tympanium was or where ever new place you choose.

Where things went wrong is the repairs & connections done in past were not quality workmanship. It is what it is. You just move forward doing it all perfectly.

You can cut all the bullets off if you want. If decide to use some bullets, you MUST buy proper crimper & use proper wire diameter for bullets. Or solder them. C314 bullet can use 14 stand or 16g wire. If you use 16g wire crimp it by feel. Not the clicker. C314 solders very well with electronics solder from Ace Hardware. DO NOT use what are sold as solder on bullets. The hole is too large of diameter & are much harder to solder. Crimping is better. But... Crimper tool is $100.
Don