Wiring Question

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I've finally had enough of the niggling (and sometimes not so niggling) electrical problems on my '73 Roadster. I recently had an obvious electrical roadside breakdown that spurred me into getting a new wiring harness to replace the oily, cruddy bird's nest of an excuse I've been putting up with. So far I've removed the old harness and put the new one in its place to begin piecing it all together. I believe the possible outcomes are: 1)Potentially getting kicked off this forum for all the annoying questions I'll eventually ask, 2) Taking it to a competent electrician after getting disgusted with my ignorant attempts, 3) Push the whole thing into the river, 4) Wire it up wrong and burn down the bike, garage, house, and half the neighborhood.

Maybe not #3, since I've too much invested in this, monetarily and emotionally, but this will tax my abilities, mind you. I believe I have the major components wired properly, such as the regulator (bypassing zener, rectifier, and capacitor). Ignition switch, and ignition system, Boyer MKIII. This seems to be the easy stuff, but the rest of the crap like the wiring to the headlight harness and handlebars and who knows what else is imposing to me.

My 1st question is, and I remember reading it here before but can't find it again, that rubber-foam block thingamajig with the metal tubes in it that serves as the terminal junction between the harness and the various components; Do I replace it? I know some say no. Where would I get a replacement anyway? If I don't replace it, then what's the best way to put together the all male-connectors, then? (That just sounds wrong, doesn't it?)

Is it best to forgo all the rubber junk and put it all together with new connectors? I know there's people here that have put together so many of these things that they could do it in their sleep, but I've never attempted this before. Also, several of what were bullet connectors on the orignal loom are now spade connectors on the new one. They would have to be, as I now have a surfeit of bullet connectors on the bike with no mates.

And another thing. I've studied the schematics and the harness closely, but not to excruciating detail. I'm as sure that this is the right harness as is possible, but has anyone had the experience of the wiring codes being inaccurate? Because if it's not according to Hoyle, I'm screwed. It just seems as I compare the scheme to the wires, they're mostly right, but then I'm not sure, because the schematic doesn't read to me like a road map, like my mind would generally work, but more like wires drawn with absolutely no consideration given to actual position on the bike. I know that's how they do it and probably have to for page size reasons or something, but I guess I'm too left-brained for that. It just appears that certain wires share connections that are not altogether clear in the drawings, or vice versa, particularly.

It probably all comes together in the end, I'm sure. It just doesn't look that way to me. OK, enough indulging my insecurities. Can anyone answer my questions? There will be many to follow, I'm afraid.
 

grandpaul

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I dislike the OEM style double-female connectors, but they are the ticket unless you want to personally re-work one each of the appropriate wires from a male to female in order to eliminate several possible future problems.

No, the color codes don't always play out according to plan for a multitude of reasons, the most typical being mismatched parts from other year/model bikes that WILL work, just different colored wires.

Wiring schematics are done different ways, the Japanese tended to GENERALLY lay them out in a physically corresponding "map" layout with relation to the components on the actual bike. I think the Brits laid them out in the best way possible to minimize "crossover" of various wires in the layout, for simplicity (believe it or not).
 

Ron L

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My 1st question is, and I remember reading it here before but can't find it again, that rubber-foam block thingamajig with the metal tubes in it that serves as the terminal junction between the harness and the various components; Do I replace it?

I believe this connector is the major contributor to the poor connections on old harnesses. One of the reasons I prefer to make my own harness is to eliminate this. But since you have a stock harness you need to deal with it. My choice would be to replace the multi connector with individual single bullet sleeves. Use a little dielectric (bulb) grease on each bullet to ease assembly and retard corrosion. Single, double, four-way, and five-way connectors are available from our friends at BritishWiring.com.

Is it best to forgo all the rubber junk and put it all together with new connectors?

Personal preference here. Depending on the circuit, I use Lucas bullet connectors, Ripart brass crimp bullets, or Posi-Lock connectors. I don't like in-line male/female spades, but use hi-quality non-insulated crimp spade connectors where necessary and shrink-tube the entire connection. For multi-wire connections like leads from handlebar switches, I like using weather-head connectors with individual pin seals. These are available in flat or rectangular and two, four, and six connection blocks.
As GrandPaul says for three way or four way common connections, sometimes the double bullet connectors are your best solution.

I'm as sure that this is the right harness as is possible, but has anyone had the experience of the wiring codes being inaccurate?

I have never had an issue with the factory wiring diagrams not following color codes. In fact, the colors make understanding the system simpler.
White wires are always hot when switch is on, Brown/Blue is always hot leads from the battery and not switched. Blue with different tracers are always headlight connections, etc. Study the diagrams and you can see the logic.

It just seems as I compare the scheme to the wires, they're mostly right, but then I'm not sure, because the schematic doesn't read to me like a road map,

You are right, a wiring diagram is not a road map, but a key to what color connection leads where. As I stated above, use the diagram to understand the logic of the circuits, then follow the color code to find the connection. A wiring diagram, for instance, will not tell you where to find the warning light assimilator. It will however, tell you how that warning light assimilator is wired. If your wiring diagram tells you the rectifier should have a Brown/Blue connection, a nearby red wire will NOT be correct.
This is why when people ask for a wiring diagram so they can build their own harness, I send them to the factory diagram and suggest they stick with factory color wiring where ever possible.
Even when adding relays and fuse panels, using the stock colors where possible makes it much simpler to trouble shoot. If two or more wires share a connection they should be the same color!
 
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That multiple connector block is no longer available, AFAIK. Single and double connectors are still available.

If the rubber is still decent, and the metal sleeves are still complete, the original block is fine to re-use. The problem with these double-female connectors is that the metal sleeves fatigue and break, even though the rubber casing still looks good.

I ended up replacing about 2/3 of my original connectors with new. I also used the OEM-replacement main harness, complete with its fabric sleeve. The front (headlight) harness, and switches are still original, but I had to re-solder about half the wires in the switches.
 

Ron L

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I also used the OEM-replacement main harness, complete with its fabric sleeve.

This is the second reference I have seen to a cloth covered 850 harness. I thought the last cloth covered harnesses were on the '70 or '71 models? I have never seen a '72 or later original harness with a cloth cover. Were there both plastic and cloth covered harnesses used in the late models?
 
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Ron L said:
I also used the OEM-replacement main harness, complete with its fabric sleeve.

This is the second reference I have seen to a cloth covered 850 harness. I thought the last cloth covered harnesses were on the '70 or '71 models? I have never seen a '72 or later original harness with a cloth cover. Were there both plastic and cloth covered harnesses used in the late models?

I don't know if it is correct, but mine came in an Andover Norton bag, and all the wire colors matched the wiring diagram.
 
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The rubber bullet connectors in the stock wiring harness are an open invitation for the Prince of Darkness to pay you a visit. Recommend that you make your own wiring harness and do away with all those unreliable connectors. Instead hard solder every connnection in the harness. The rubber connectors are there so you can take the bike apart, but if you have a reliable wiring harness the bike will always run. If you have to take the bike apart cut the wire and resolder back together.
In addition it is recommended that you do not buy the cheap wire from the auto shop. The wiring harnesses that have been dismantled have been found to be corroded inside the insulation, invisible during inspection. Instead go to the marine supply and buy marine wire. This wire comes pretinned its entire length and has a well bonded insulation much superior (reliable) than the cheap Chinese stuff commonly available.
 
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norsa1 said:
The rubber bullet connectors in the stock wiring harness are an open invitation for the Prince of Darkness to pay you a visit. Recommend that you make your own wiring harness and do away with all those unreliable connectors. Instead hard solder every connnection in the harness. The rubber connectors are there so you can take the bike apart, but if you have a reliable wiring harness the bike will always run. If you have to take the bike apart cut the wire and resolder back together.
In addition it is recommended that you do not buy the cheap wire from the auto shop. The wiring harnesses that have been dismantled have been found to be corroded inside the insulation, invisible during inspection. Instead go to the marine supply and buy marine wire. This wire comes pretinned its entire length and has a well bonded insulation much superior (reliable) than the cheap Chinese stuff commonly available.

I have used rubber female-female connectors and male bullets for a long time 15 years and have had only one problem admittedly that was losing the Boyer ignition power whilst on the outside lane of a motorway not so amusing but otherwise fine, I have used a non setting sealing compound used in external underground garden wiring on the connections under the tank.Its personal choice I guess. I dislike the cheapo spade connectors commonly sold as they look bad and seem more prone to failure than the original rubber bullet connections (I had some on a 500 dommie) its personal choice I guess. I do check all connections each year for signs of water ingress and other probs.
 
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