81 Wiring Nightmare

[thirdgen427]

OK so i got a real stumper, ill start off with this its a 1981 GS1100E with 14,000 miles on it and were talking original tires mint and always garage kept. So last year i noticed that the bike was not charging the battery, everything else worked great except for that, also noticed that the rectifier wires were getting so hot that they were melting the insulation and the plastic covers on the connections. So a simple rectifier replacement took care of that, but then one day riding home all the lights (dash,headlamp,brake,and turn) dimmed out as if they were only getting 6V. After i got barley got home the whole bike just shut off as if you had disconnected the battery cable, no power anywhere but all the fuses were still good. So i replaced the battery cables which somewhat fixed it but for some reason the whole check panel is lit up and i have no turn signals, or brake lights. the high and low work fine as do all the running lights except for the signals. also my neutral light stays on and sometimes the oil light will also. And to throw off whatever you were thinking it still has this prob with the regulator unplugged (while the bike is not running of course) also still has brake light prob with turn signals unplugged. i pulled back the sheathing in the main harness and have spent days looking for burnt wires or bad connections but found nothing the harness is 100% un hacked stock. i even tried replacing the battery and this led to the bike not starting with the start button, but if i jump power to the trigger wire on the solenoid it fires right up, ignition is not effected. any help would be greatly appreciated. Thanks Brad

[duaneage]

Measure the voltage across the battery with the engine running. I bet it's not charging. Recheck the connections to the RR and check the stator voltage output.

Should generate 60 - 90 volts AC between any two yellow leads. Unplug from the RR for this test. Make sure the meter is set for AC and do not touch the bare wires either together, or with your fingers.

[BassCliff]

Greetings and Salutations!!

Hi Mr. thirdgen247,

What Mr. duaneage is trying to say is to go through the Stator Papers to diagnose your charging system. There are other maintenance tasks in your "mega-welcome". Let's get started.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[thirdgen427]

OK checked the voltage again, with the bike running at 4500RPM (and warmed up) the voltage across the battery is 15.1V and at 5000RPM the voltage off the stator is 83V AC. i am also getting the full voltage in the fuse box, at the connector for the ignition switch, and after the switch and to the tail light. i also have the factory service manual from the dealer that i have been referencing from.

[thirdgen427]

thanks for the friendly welcome, it seems like this is the best place to get answers for this bike. also just wanted to add if i put a meter across the top three circuits in the fuse box, positive to the fuse, neg. to the neg. battery terminal, it reads 12.54V dc(with the bike off) and drops to 2.34Vdc when the key is turned. now here's the confusing part if i switch the leads and put the neg. on the fuse and the positive on the positive terminal with the key turned i get 10.21V DC. i tried back tracking these circuits with the wiring diagram and they share two wires an orange with a green tracer and an orange with a red tracer which run to just about evey lighted circuit on the bike.

[BassCliff]

Hi,

You've got some nasty voltage drop occurring somewhere. You're going to have to clean up your wiring harness. See my site for tips. Check/clean/repair every electrical connection and ground on the entire wiring harness. This includes the fuse box, the ignition switch, the big fat ground wire between the negative battery terminal and the bottom of the engine, blinker stalks, inside the molex connectors, everything. Yes, it's tedious and time consuming but your bike will love you for it. It's almost 30 years old and needs some TLC.


When you're done there, go through the maintenance lists in your "mega-welcome".


Thank you for your indulgence,

BassCliff

[Matchless]

BassCliff says it! Also have a closer look at the ignition switch connector, as the current from the main fuse flows through it and is switched back to the other fuses. I found that the measly little connector pins can be damaged or corroded and cause similar problems. Change it with a faston (spade) multi pin connector.

[duaneage]

I cleaned an ignition switch on a 650L and the coil voltage went from 9.6 to 12.5

Didn't even need to add a relay for that fix.