frustrating wiring problem

[diegos_den87]

hi all, having some electrical problems with my 79 gs750L. I got the bike a few months ago, and have spent a good deal of time(and money) sorting out little problems and modernizing it's appearance a bit. I recently encountered a new problem in the electrical department. The only modification I've made to the electrical system are some new turn signals. everything was working fine(signals, headlight, ignition, starter, etc.) until i tried to hook up the brake switch on my new nissin radial master cylinder. it killed all the dash lights, head/tail light, and horn and blew the signal fuse. the starter was still working as well as the ignition, as the bike would start and run. I proceeded to inspect all grounds I could find, and pull apart and clean all connections. And, viola! it all worked again. I then reassembled everything, filled the tank and started it up. as I sat atop the angry beast, listening to the hellish roar of that engine reverberate through the garage, I was transported to my happy place. a mental image of a long straightaway, gripping and turning the throttle, pushing through the morning dew. Anticipating the fairytale left turn, i popped on my blinker and... lost power again. i hit the kill switch in frustrated disbelief. turned the key a few times, nothing. after another disassembly and some more guesswork with the connections, she came back, but only the dash lights. when i try the turn signal, all power is lost. this happened 2 or 3 more times, power came back, just to be snuffed out by the turn signal. and now, i have no power, to anything. I'm beyond confused here, can anyone help me out? And if anyone could point me in the direction of a wiring diagram specifically for the 79, that would be great, as my Clymer is not fully accurate.

[Headspin]

Not sure what the overall issue is.... but go back to the point before you hooked up the brake light... it all seems to stem from there.
Do you have a meter?
A light bulb and battery can also help isolate shorts if not..

I know the feeling of deflation you are talking about... we do it for those good times though

Good luck!

[lucabond]

Like the last post said it would seem the new brake switch is shorting the power to the turn brake light. If you disconnect the new switch does everything work as before except the brake lights ? If you have a meter check the new switch and see if it shorts to the body of the switch when squeezed or does it just connect the 2 wires together. It does have 2 wires I would think. I'm not familur with the new brake switch you have so its had give a opinion. Good luck

[diegos_den87]

Beer.

The brake light switch was only hooked up momentarily, I unhooked it when i lost power the first time. And yes I have a meter, but my lack of electrical knowledge keeps it from being a very useful tool. It has many settings, all of which are marked by less than self-explanatory symbols. I have established the V dc setting and the resistance setting though i don't really know how to usefully implement the latter. I was hoping maybe somebody out there has had a similar problem or knew of an obvious culprit. But I'm pretty much clueless so any suggestions would be greatly appreciated. I'm also having trouble because the Clymer manual's wiring diagram is not accurate. I'm guessing it's the pre-79 diagram because it has only one fuse, the main. my bike has 5, the 4 on the fusebox and one other, seemingly useless one above it.(no current, no connections)- don't ask me it was like that when I got it. Thank you all in advance for any help. Your assistance gets me back on the road faster, therefore I love you all.

[Joe Nardy]

Start unplugging things until the fuses stop blowing. Plug whatever you unplugged back in one at a time until the fuse blows again. Figure out what circuit the last think you plugged back in relates to.

Thanks,
Joe

[diegos_den87]

I wish it was that simple, the fuse only blew the one time. I can get current to the fuses as long as i unplug the blue wire coming from the dash(neutral indicator light I think) and the orange w/ green stripe in the 6-circuit connector going to the dash. when these connections are made, i turn on the ignition and lose current to all but the main. but I get no power to anything in any configuration as far as i can tell.

[avastyematey]

I had that problem too, it turned out that where the turn signal was going into the frame the wire had pinched and it was shorting there. maybe that will help.

[diegos_den87]

I had that problem too, it turned out that where the turn signal was going into the frame the wire had pinched and it was shorting there. maybe that will help.

where exactly did this pinch occur?

[avastyematey]

Look right inside the turn signal assembly where the wires come out. My short occured right there. The assembly was pinching against the body of the bike and pinching the two wires.
It was in a place that I couldn't attack with electrical tape, but hot glue worked fine to seperate and insulate the wires.
good luck