Intermittent Electrical Issue

[duaneage]

Your problem is most likely a bad connector or switch, For the bike to go completely dead this would be in one of only a few places.

The Fuse block (if equipped as yours is) would have a main fuse that could internally be bad. Replace the fuse with a new one.

After the fuse block there is a multi connector. The red wire goes in, the orange wires are all fused lines that go to various places on the bike. Check the red wire's connectors on both sides of the plugs. Make sure they are not deteriorated.

Move to the headlight bucket and find the red wire going to the ignition switch, usually it is a green connector. Check the wires and pins there, wiggle these connectors with the key on and see if the power cuts out out. If that is not it move to the ignition switch, which is most likely the culprit.

The high charging voltage is a sure sign of a voltage drop somewhere. You can do the famous coil relay mod but that won't provide you with lights and other necessities. Cleaning the contacts would be the best and cheapest course using spray contact cleaner available from Radio Shack.

The only points that would effective shut off the bike are the main fuse, connectors to the ignition switch, and the ignition switch itself. The same connectors that feed the ignition switch also return voltage back to the fuse block where it is distributed out. Once in the fuse block, you might loose lights or ignition, but not both.

The ignition switch is the most likely problem, I've seen them drop 3 volts or more. They get rained on and sit up in front. The RR would not shut down anything like that. It's not wired in series, but in parallel. If it did have a problem the main fuse would open up once and for all. The only point that can turn off the entire bike is the primary power circuit described above since it is wired in series.

PM me if you would like to work on this over the phone, I can help diagnose these types of problems.

 

[850 Combat]

Run the sensor wire to the battery, and it might stop overcharging. Mine did. I had too much voltage drop in the orange switched lead. Looks like you do too, only more so.

I also suspect your ignition switch. Pe Duanage, that is where the voltage drop is in the switched lead as well.

 

[79 sh850]

I also would suspect the ignition switch. The lock was so worn on my GS400 that the weight of the ignition key and leather fob alone would cause it to rattle itself into the off position randomly. The only solution was to wreck the bike in a corner and replace it with a GS425 model of the same vintage. The ignition switch on this bike failed halfway up the Second Narrows bridge when one of the wires broke off the back of it at the solder joint. I guess the point is you can't trust these thing electrically or mechanically after so many years of use.

I would eliminate the switch from the circuit and jumper the connections temporarily at the green connector behind the headlamp as mentioned so that the bike will run without it, go for a ride and see if the problem goes away.

The only other thing that I could think of that could be causing this is a massive short to ground somewhere in the wiring ahead of the main fuse. I sincerely doubt that this is the case since the acrid smoke and smell of burning plastic and impending fire would be dead giveaways that something was amiss.

 

[rputney01]

PM me if you would like to work on this over the phone, I can help diagnose these types of problems.

I haven't had a chance to get back to the bike yet this morning and probably won't until late this afternoon. I run the checks suggested and report back. The ignition switch is one of the few electrical components I haven't replaced, so perhaps it is time.

Thanks to everyone for your help.

 

[rputney01]

I went through and cleaned all the connectors and used dielectric grease when I put them back together. They all appear tight and I can't replicate the failure from fiddling with the wires in the headlight bucket. It looks like I'll be ordering a new ignition switch. I did spray some contact cleaner into the existing switch and turned the key a few times. Right now, the bike seems to start and run fine.

I can't figure out why I have such a voltage drop coming from a fairly new fuse block. I cleaned those connectors as well, which helped some, but the drop is still over a volt. I didn't have time this afternoon, but tomorrow I'll take the fuse block off and check the drop right off the block. Oh, and I did change the main fuse as well, but it looks fine and the circuit tests the same either way.

Again, thanks to everyone for the help and advice.

 

[Matchless]

Okay, some additional info. I have a Duaneage Honda RR on the bike and have had since this spring. The negative (green) is wired directly to the negative battery post. Thus, no voltage drop on the negative side. On the positive, I get .02 drop from the RR to the positive post. The black sense wire is connected to the orange/green wire for the brake light.

Is the RR the problem? Should I wire an additional negative from the RR bolt to the negative? Is the connection for the sense wire an issue?

If you temporary connect the black sensing wire directly to the battery, you should get an improvement (lower) charging voltage, which then indicates a voltage drop between the battery and the brake light, usually the ignition switch, but could also be any connector or fuse in that path.

 

[duaneage]

The voltage drop is trouble waiting to happen. Anytime you see voltage being dropped heat is generated. And the poor connection will get worse, increasing the drop and the damage. The rear of the fuse box is removable on most of these bikes, the connections are pinned together with rivots. Solder the connections instead and that should do it. Also clean the fuse connections with a brass brush until they are shiny. I've seen one of the fuse holders break off due to a crack. It was not providing enough force to hold the fuse and you could see sparks between the fuse and he clip.

These bikes are old and things like this happen. Once corrected they are good for another 25 years.