I am building my own wiring harness

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My 74 850mk2. I removed the 47 year old wiring harness because it was old although almost untouched. I have replaced it with a Wassells/Lucas 54960723 harness which fits really well, is actually far better made than I expected for the price, and is a very worthwhile purchase. But……..

I am so used to simple plug and play harnesses on all of my Jap and modern bikes, that the minefield of connectors along with the 2 handlebar switch harnesses is really starting to annoy me. There must be a better way I reckon.

I have several mods that negate a lot of the stock wiring, EI, Podtronics, CNW coil, ECM warning light box, and so I’ve made a start.

Firstly, I’ve taken my stock harness and carefully laid it out and removed all of the wrapping. Then I’ve removed every wire that is no longer needed, eg capacitor, coils, ballast resistor, condensers. Additionally there are a number of dead end wires that have been removed. That has made quite a difference already. It is surprising how many wires it’s now possible to do away with.

I’ve ordered all of the colours of wire I need, and heavier duty for the main power and Earth wires. Also a selection of 2, 3 and 4 connector male/female plugs to connect the 2 ’bar switches to the main harness and the headlamp harness. I’m wondering if I can find a way to go direct to the headlight with some of the wires to eliminate joints. I’ll find that out when I lay it out on the bike itself.
 

Craig

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I made my harness up maybe 20yrs on now , I based it loosely on a “simplified wire diagram” for Brit twins in an old British Cycle catalogue , the place in Nova Scotia …. got some spools of different coloured wire one gauge larger than original …. still working great …. No directionals, no switches on head lamp bucket , horn, brake lights, headlamp and ignition … use left side switch for headlamp on/off and dip , horn below …. right side no switch just clamp from CNW brembo upgrade ….. think you will be very pleased with your new slimmed down harness !
 
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Ah, not very good before and after pics of the original harness. But I reckon you can see how slimmed down the ‘front’ end of the harness now is. At the rear all that’s gone is the zener diode lead. When I rebuild it with new cables I will add in a better earth system.
 

cliffa

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A worthwhile upgrade. Where do you plan on connecting the handlebar switches, in the headlight shell ?

Cheers,

cliffa.
 

Craig

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That looks good , still a lot more wire than I used ….
 
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A worthwhile upgrade. Where do you plan on connecting the handlebar switches, in the headlight shell ?

Cheers,

cliffa.
It’s a work in progress at the moment. My pencilled idea at the moment splits the wiring for both switches into two sets of connectors each rather than 5 individuals each.

left switch = indicators and horn, the kill switch is eliminated going to the main loom. The 2 indicator cables for left and right to go into the headlamp shell connector

right switch = dip/main/ flash, starter. 3 cables to the headlight shell, 2 to the loom.

I intend to make a dry-run build without connectors to enable me to stagger how the connectors can be arranged under the tank. Unlike the mass meeting with the existing Lucas bullets.

I think it can work.

Maybe…… :)
 

cliffa

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Haha :)

By they way, I re-worked my switches, so the starter button is bottom right, kill top right, high / low beam right center, horn left lower, flasher left upper and Indicators left paddle. it's much easier to go from one bike to the other now, as the switch positions are nearer the norm. I kept the wiring colour codes the same by un-soldering them from the switches and swapping them around.
 

grandpaul

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You can also fab up a separate, simple, harness just for the blinkers if ever needed. No need to split open the good work that will be done.
 
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Sorry, I don’t follow you, my thinking head isn’t working too well today. I plan to take the 2 wires that power the left and right flashers via a double connector directly into the headlamp. The remaining wires will connect to the main harness along the backbone. Am I missing something in your suggestion?
You can also fab up a separate, simple, harness just for the blinkers if ever needed. No need to split open the good work that will be done
 

grandpaul

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Sorry, I don’t follow you, my thinking head isn’t working too well today. I plan to take the 2 wires that power the left and right flashers via a double connector directly into the headlamp. The remaining wires will connect to the main harness along the backbone. Am I missing something in your suggestion?
I thought you were NOT going to have flashers.

I must have mis-read something...
 
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Yep ’tis you ;) this time, normally it’s the way I’ve written it.

I've just spent 2 days, it seems, trying to get some volts into my new Lithium battery. The pukka charger didn’t want to know, it kept switching off. So, I finally hooked it up to a lead acid charger for a few hours until it finally read 11.5volts from an initial 3.2v and then the lithium only charger said it was OK perhaps now I’ll work properly. Technology ain’t what it used to be :mad:
 
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and the simple answer is - no, it isn’t charging correctly. It still switches off. So, one last chance it’s back on a lead acid charger and I’ll see how it is later on. I’m really not expecting any success so I’ll bend someone’s ear on Monday.
 

TomU

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You may be using the wrong charger

 
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That’s what I’ve got. Along with 3x Optimate 4s. And another smart charger that doesn’t want to play either.
I reckon the new Shorai is most likely toast.
 

Fast Eddie

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Shorai do their own charger, it does t connect to the terminals like ‘normal’ charges, it plugs into the multi pin plug in the middle of the battery.

Have you only just bought it, or is it old?
 
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Nope, the battery is brand new. As is my Optimate. One last chance then the Optimate goes back, Internet sale so I can return it no quibble, then argue with the Shorai people I guess.
 

Fast Eddie

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IIRC Shorai batteries need charging when first bought?

I’ve used a lot of Shorai batteries and only had one go down, and that was one that I ran too flat. I’ve only ever used the Shorai charger though, so don’t know owt about compatibility with others.
 
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