Burned wires need advice

[Matt K]

OK, Today I started to try to figure out what my problem is. As I was going through the manual it told me to unplug a connector under the right side cover. When I started looking around at the wires there I noticed a VERY fired wire. It appears to be black with a white or yellow stripe. It goes up to the wiring harness that goes under a gas tank, and down to a box behind the rear break master cylinder. I removed the box.

So my questions are these. What is this box. Do I need to replace it or just fix the wire from it? If I need to replace it any idea what it will cost? Of course I need to replace the wire in the harness, but is there anything else that I could have fried, anything else that I need to look at?

Thank you for all your help!

[t3rmin]

Sounds like the regulator/rectifier. If the damaged part of the wire doesn't go down into the box, you'd probably be OK just splicing and replacing the scorched section of wire. It may have fried in the first place because of a bad (high resistance) connection, so make sure the connectors on that wire are clean and good. Heck, check/clean/replace ALL of the connectors you can find...

Otherwise you're looking at an expensive replacement, unless you go the Honda r/r route. Might as well try to salvage what you've got first.

Also might want to go through the stator papers in the tech section of the main site and check over the whole charging system.

[Matt K]

I thought that that part was on the same side of the bike as the fuse panel? The box that I am talking about is on the opposite side of the bike.

Sounds like the regulator/rectifier.

[rgierer]

I don't know the specifics about your wire, but I can attest that on both of the 82's I have had I have found the connector from the R/R to be fried and wires burned and brittle resulting in rewirring that little section. It has been a key element of a successful charging system. I always assume the r/r has gotten so hot it just used up the wires.

[Tom MLC]

Matt, maybe you posted somewhere else. I would like to know what the nature of the problem you're trying to troubleshoot.

On my 1100, the black wire with stripe is a ground. Regardless if it's the turn signal circuit, or the tank level circuit, etc. You could easily lose track of the wire that's fried, and then find another black with stripe wire in the headlight bucket, and think it's the same wire. More than likely it's not.

But let's get back to the challenge you have. Maybe just fixing that bad section of wire is all you need to do.

[renobruce]

The black box behind the rear master cylider is the self-cancelling unit for your turn signals

[RobGS850L]

I'm with Tom on this one. Fix it then trace. I do have an all stock 850 and I can take a look at it and see what it's for but more than likely the problem is a bad connector. Clean the surface and put a little dialectric grease on it and you should be fine. I had wires frying all over the place and things not working on the 850 shortly after I bought it and started finding black connectors. Cleaned them up and haven't replaced a thing.

Update on this post;
If my fingers weren't so slow at typing I would have posted before Bruce and wouldn't look quite so dumb. :roll:

[Matt K]

I started with this problem:
Ok yesterday I started my bike and let it idle for a few minuets. I then did a dumb thing and left the keys in it and in the on position. So I had a dead battery. I pulled the battery and charged it.

Today I put it back in. reconnected everything and tried to start the bike. No Go. The battery is just fine. The starter is spinning the engine with gusto. I can smell gas in the air box. But I don’t think I have spark. I pulled one plug wire and lay it on its side, and tried to start the engine. I did not see any spark. I also put an Allen wrench in the wire to cut the distance for the spark to jump. I did this on both 1 and 4 cylinder. I have never worked on a motorcycle and only have limited work on a car. I just don’t think I have spark and I don’t know what I did to make this happen. I did also check the fuses and all connections around the battery to make sure I did not accidentally disconnect one of them.

Where do I go to from here?

Now I have a burned wire that leads to a small black box that I believe controls my spark, but I am not entirely sure. I don’t have self canceling turn signals so that would not be it.


Any help or advice would be great.

Matt, maybe you posted somewhere else. I would like to know what the nature of the problem you're trying to troubleshoot.

On my 1100, the black wire with stripe is a ground. Regardless if it's the turn signal circuit, or the tank level circuit, etc. You could easily lose track of the wire that's fried, and then find another black with stripe wire in the headlight bucket, and think it's the same wire. More than likely it's not.

But let's get back to the challenge you have. Maybe just fixing that bad section of wire is all you need to do.

[renobruce]

Can you post a pic of this box?

[Matt K]

Its at home, but tonight I can try.

It is held to the bike with 2 bolts and has 2 pig tails. One with 2 wires, green and blue. The other has several wires( might be 5 or 6), these connect to the main wiring harness.

Can you post a pic of this box?

[RobGS850L]

I have a black box on my 850 with the black/white wire and it's not ignition related so far that I can remember. My ECM is under the battery. I think Bruce's box is related to the blinkers as is mine I think. If somethings drawing so much juice that it's causing a wire to burn I'd start to look at your connections to see if they have good continuity. Sometimes they will draw so much other things may not work. Take a look.

[Tom MLC]

You should have self canceling turn sigs on an '81 750, in my opinion. My limited experience tells me earlier models ('77 & some '78's) did not. I could be wrong, so don't take that as gospel. The box that Bruce describes definately is for self canceling sigs. These boxes are expensive to replace, so most folks simply live with manual operation of the sigs. Repair that wire though.

But this is probably not your main problem. You say you left the key on for a while. I assume the headlight was also on. Check inside the headlight bucket for wires that overheated. I found four burned wires on my 1000 recently.

After that, check for power at the coils. And check all wiring under the air box and the LEFT side cover. If one wire can fry, so can others.

By the way, do you have a Clymer's manual? There should be a wiring diagram in the back. Might help you out a lot.

[renobruce]

Does this look like the part you are talking about?

[Matt K]

That is exactly the part that I am talking about!

Does this look like the part you are talking about?

[renobruce]

That's your CDI box for your electronic ignition. Fix that wire. If it works, then your good. If it doesn't work you probably fried it by leaving the ignition on so long. You might get lucky and find a used one on ebay that actually works, or you can get rid of it all together and go with a dyna S ignition. A new CDI is more than a new Dyna S