New wiring harness for 850 Commando

Hello again. I have a 74 850 Commando I am restoring. Does anyone make a good aftermarket wiring harness to replace that piece of crap Lucas Beast. Hopefully something simpler??? I will be running turn signals and boyer ign. along with normal stuff needed---Thanks

Pretty simple to make your own. I'd stick with original color codes. Correct color in modern wire is available from British Wiring. Think it through and draw a sketch. Use as few connections as possible. Decide if you want to use bullet connectors or a modern pin connectors. Consider adding additional fuses and using relays for key items such as ignition, lights, horn, anything that runs through the handlebar switches. This adds some complexity, but also reliability.

Hi:
I got mine from TMS.
http://www.tms-motorcycles.co.uk/store/ ... cat_id=234

Top quality stuff... 8)

Does any one actually make them to order? If I specify a harness for a MKIII without Zener diode wires, power take-off wires, balast resistor wires ect can it be done? Or am I basically having to make my own. I'm I could do it but I'm an electro-retard when it comes to wiring.

Coco said:

Does any one actually make them to order? If I specify a harness for a MKIII without Zener diode wires, power take-off wires, balast resistor wires ect can it be done? Or am I basically having to make my own. I'm I could do it but I'm an electro-retard when it comes to wiring.

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Coco--

On this list, I was referred to a guy in New Zealand who makes excellent harnesses to spec.... all the correct colors and fasteners are used. Very efficient and clean work, and it arrived here at my address (U.S.) at barely over $100.00 USD.

His own response to my initial inquiry:

"Let me know what you want in the way of "extras" or variations from standard, also whether taped or braided finish, and make, model and year, of course. The looms I make are complete (main and headlight in one piece) with original colours although these are getting more difficult to get so have to import from the UK. I also use original type bullets and connectors.... Pleasing to know that people are satisfied. I work from home, have made and sold over 1000 harnesses to date. (retired telecom technician and motorcyclist of 58 years)."

His name is Bruce Carrad, and his e-mail address is:

alison.bruce@clear.net.nz

Having said that, I goofed up in not giving him all the changes I planned on making, so I have a harness that does not accommodate a future 3 phase alternator, non-stock switches, headlight relay, etc. So in the end I may end up just doing my own from scratch.

Cheers--

wrench

Wrench you rule. Thanks a bunch. For some reason I am really weary of doing my own harness as I seem quite afraid of doing any electrical work on my bike. I will get in touch with Bruce.

Mark Cigainero said:

Hello again. I have a 74 850 Commando I am restoring. Does anyone make a good aftermarket wiring harness to replace that piece of crap Lucas Beast. Hopefully something simpler??? I will be running turn signals and boyer ign. along with normal stuff needed---Thanks

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Colin Farrington in the UK can make you a custom harness. He makes custom harnesses for AJS and Matchless bikes and seems to have many satisfied customers.

http://www.catmando-services.co.uk

I think it may have been me who refered Wrench to Bruce. I could not recommend him high enough. I sent him the wirng info on the Podtronics box, Pazon ign, Dyna coils etc and where I wanted to locate things and he had the loom on my doorstep in 10 days! Everything connected straight up.
great service.

shedweller said:

I think it may have been me who refered Wrench to Bruce. I could not recommend him high enough. I sent him the wirng info on the Podtronics box, Pazon ign, Dyna coils etc and where I wanted to locate things and he had the loom on my doorstep in 10 days! Everything connected straight up.
great service.

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I owe you a big THANKS on that referral shedweller, and could recommend Bruce to anyone based on his service and price. Completely no frills and just delivers the product for a very good price and (plus) is a great guy.

Coco, thanks for the thanks. I too was/am very cautious about doing my own wiring, but after reading up on it - and my brain doesn't wrap around electricity that easily - it is completely doable to make your own as well. One book I recently bought is Motorcycle Electrical Systems: Troubleshooting and Repair (Motorbooks Workshop) by Tracy Martin. The first two chapters on "theory" really are helping me make sense of the process. In addition, there is a new book coming out that I ~think will be very practical: How to: Advanced Custom Motorcycle Wiring by Jeff Zielinski --its publication date has been delayed until the end of the month (according to the good folks at White Horse Press) but I suspect it may be a very hands-on approach to dealing with wiring.

In addition, the following online article is very helpful:

http://www.angelfire.com/biz/snwvlly/bikes/lucwire.htm

He doesn't cover a lot of special modifications (relays, 3-phase alternator, loads of fuses, et al) in this particular article, but I suspect if one followed his advice to a T, it would be an adequate approach to wiring our Nortons. I would be interested in hearing what others here might think of his approach, though. I also just happen to have a parallel philosophy about bikes with the author, which comes through a bit in the article as well.

The "theory" part of wiring I can't emphasize enough, and knowing what part does what..... I got such good advice here earlier this year from folks on this list, I was just to green to really know how good and correct it was.

Cheers--

wrench

I've seen more than one Norton owner here who wires for relays. I don't understand why. A relay is nothing more than an electrically operated switch. In the case of the Norton, I assume owners are using relays to increase current carrying capacity (ampacity) of the switched circuit. Rather than the manual switch carrying the full current of the device; lights, horn, etc., the switch only energizes the relay coil for the specific device which requires less current than the device itself. I never found the ampacity of the stock Lucas switches lacking. Now, if you are running heated grips, heated seat, extra lighting or whatever, then it makes sense. Using relays provides no benefit, for a stock Norton electrical system, that I can see.

I never found the ampacity of the stock Lucas switches lacking.

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Unfortunately, Jim, I have. Headlights flickering from a poor ignition switch contact. High beam weak from poor connection in the handlebar switch. Ignition failure from corroded kill switch. And most often, horn sounds weakly due to the inability of the horn button to pass enough current to make the reed vibrate fast enough. Because relays do not require much amperage, I find all these systems work better and more reliably with relays (and separate fused circuits).

Even on my R1100RS, adding headlight relays improved the brightness of the headlight. (This is the one biggest weakness of this bike, a poor headlight).

wrench said:

Coco, thanks for the thanks. I too was/am very cautious about doing my own wiring, but after reading up on it - and my brain doesn't wrap around electricity that easily - it is completely doable to make your own as well. One book I recently bought is Motorcycle Electrical Systems: Troubleshooting and Repair (Motorbooks Workshop) by Tracy Martin. The first two chapters on "theory" really are helping me make sense of the process. In addition, there is a new book coming out that I ~think will be very practical: How to: Advanced Custom Motorcycle Wiring by Jeff Zielinski --its publication date has been delayed until the end of the month (according to the good folks at White Horse Press) but I suspect it may be a very hands-on approach to dealing with wiring.

In addition, the following online article is very helpful:

http://www.angelfire.com/biz/snwvlly/bikes/lucwire.htm

He doesn't cover a lot of special modifications (relays, 3-phase alternator, loads of fuses, et al) in this particular article, but I suspect if one followed his advice to a T, it would be an adequate approach to wiring our Nortons. I would be interested in hearing what others here might think of his approach, though. I also just happen to have a parallel philosophy about bikes with the author, which comes through a bit in the article as well.

The "theory" part of wiring I can't emphasize enough, and knowing what part does what..... I got such good advice here earlier this year from folks on this list, I was just to green to really know how good and correct it was.

Cheers--

wrench

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Thanks wrench. It is good you posted tye links to those books since it was not even yesterday I decided I'd better try and get some kind of book to explain wiring.

I am just about to order some parts from Walridge and they sell a Haynes manual dedicated to electronics. Anyone have experience with that one? Is it a hit or is it s**t?

Ron,

Unfortunately, Jim, I have. Headlights flickering from a poor ignition switch contact

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That's a pretty good reason to go to relays, what with the cost of a new switch(s). Does that ignition switch cause the bike to run poorly, too? I just have never had (thank the Lucas gods) any switch problems. I suppose if the relays are of good quality and are properly mounted and wired correctly, which I'm certain is the case with yours, then it might not be a bad bet.

Does that ignition switch cause the bike to run poorly, too?

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The switch issue usually manifests itself by disconnecting when you hit a bump or when you switch from "run" to "lights" and the engine dies! I have had them suddenly die and had to reach down and wiggle the key and it would backfire and take off again. The kill button on disc brake models is behind the master cylinder which if it begins to leak (make that when it begins to leak) corrodes the the contacts. Disassembly and cleaning and a sleeved master cylinder will solve the problem, but if you measure the voltage at the Boyer connection will often yield less voltage than at the battery. With a relay, I have never seen this happen. We all know that the Boyer likes a full 12 volts.

Ron,

I'm not trying to pick this apart, but wouldn't a faulty ignition switch cause the relay to fall out, too? I guess I don't know how the relay that supplies power to the ignition is wired. I'm assuming the contacts are directly to the battery and the coil to the swiched supply. Right?

You are correct Jim, the intermittent action of a worn ignition switch is not helped by relays. What does help is the voltage drop to the Boyer. Count the number of connections from the battery to the ignition switch to the handlebar harness to the kill switch back from the handlebar harness to the Boyer feed wire. Plus the connection of the normally closed kill switch itself. If you measue voltage accurately at the Boyer feed wire you will see a drop in voltage from your battery voltage. We all know that Boyers like full voltage to maintain a smooth advance curve.

I wire the feed from the battery, through a fuse to the relay and from the relay to the boyer connection. The trigger voltage goes through the normal path through the ignition and kill switches. I won't wire a British bike without a kill switch. I know have less than half the connectors and several feet less wire from battery to Boyer.

That's why I like a relay on the ignition. Don't get me wrong. With impeccable maintenance you can keep all your bullet connectors in good shape and your switches clean. But for the average Norton, you will still see significant voltage drop to the ignition.

What does help is the voltage drop to the Boyer.

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Guess I'd never considered that. I'll measure mine to see if I have any voltage drop. I've just never had any electrical problems (he nocks on the wooden desk) outside of the pickup wire on the Boyer breaking inside of the insulation. The more research I do about Boyer ignitions the more I'm inclined to think maybe the conventional points weren't that bad, after all.

Nahh! I wouldn't go back to points. I haven't seen an AAU in years that didn't have notches worn into the extremities of the pin slots. I have a 3# coffee can full of them because I keep thinking you should be able to smooth those notches out and harden the unit somehow. Aftermarket condensers have a bad habit of shorting out and new Lucas ones are hard to find.

The Boyer is pretty reliable overall. Set it and forget it. It starts easier than it ever did with points. The only failures I can remember are broken pickup wires, which I know now to replace with brass screws from the start., Once I had a black box quit. Other issues were always traced to the bike's wiring or connectors.

I do believe the RITA is a better unit. I have one on my e-start cafe racer (working starter) and a couple older units that are still functional. I don't like the square points cover although I have seen people make a spacer and use their stock cover. Of course it's academic since Mistral is no longer making them.

The Pazon is intriguing, but three times the cost of the Boyer.