i need electrical help...

[david]

this site is great!! i'll be here a lot!

ok,,, i've rebuilt an 81 GS1000GL that has been in storage and apart for who knows how long. I'm down to the wiring, and I've got that done to a point of trying to crank it. When trying for the first time today, a strange thing happened. The engine turned when I turned the ignition switch, without touching the starter button or anything else. It also blew the main 15amp fuse. I've tried again and the fuse blows imediately when the key is turned. It doesn't turn the motor anymore. I have no idea where to begin to start troubleshooting.

Any advise, suggestions, or comments by smarter minds than mine would help...

thanks!!!

[focus frenzy]

well it could be many places, have you tried tracing the harness from the handle bars on down to the battery?

PS: you wouldn't be in Plano would you?

[david]

no... i'm in Odessa.

yeah,,, i'm sure that the ignition system is wired correctly.
i had to get a new (used) wiring harness to wire it, and so i've traced them all. i'm pretty sure.

[DaveDanger]

It could be one of a few different things. It sounds to me like the starter relay has welded/frozen in the closed position. This would begin the starter turning over as soon as the ignition switch was turned on. The reason for that and the possible reason for the welded relay in the first place is that the starter itself may be shorted to ground internally. It could also be the starter button itself on the handlebar welded closed, but that's less likely than the relay.
In the interest of safety, and to avoid blowing more fuses... do the following.

#1 first step... Pull the main cable from the starter terminal and keep it disconnected while you run your tests. Turn the key and see if the fuse blows. If the starter or relay is part of the problem, it should not blow the fuse. Check the starter cable with a voltmeter set to something above 15 volts DC. If you have voltage there with the ignition switch on, but no starter button pushed, the relay is welded closed. If you have NO voltage at the starter cable, back up to where the heavy battery cables come into and out of the starter relay, and see how the voltage looks there. You should always see battery voltage present at the starter relay input side. You should only see voltage at the output when the starter button is pressed.

If you find no welded relay or shorted starter... you possibly have the starter wiring/cables pinched and shorted to ground somewhere along the frame.

Try these tests and post back.

G'luck.

[david]

sounds like good advice!! thanks! i'll perform those tests.
i've checked the starter button and it seems to be ok.
Here's more info on it,,, and maybe more questions.
In the new (used) wiring harness, up around the clutch lever, there were 2 yellow/green wires connected together. (don't know why) I unplugged them and one tracks to the starter button. So i connected the one (green/yellow) going to the starter button to the starter disconnect switch in the clutch, and the other green/yellow out of the disconnect switch runs to the starter relay. But that still leaves one green/yellow comming out of the harness by the handle bars that's unconnected (this is the one that was connected together when the harness came.)
?????????????????

one more thing i'm thinking about. Where should there be frame grounds,, and how many should there be?

[DaveDanger]

It sounds like the P.O. of that harness bypassed the clutch safety switch at some point. I hate the clutch safety switch myself, but I typically bypass it inside the headlight bucket so that disconnected or obviously re-routed wire connectors aren't hanging out in the open.
As far as frame grounds, my feeling is that you can't have too many of them. I have no idea how many are actually provided for in a harness, but I would install a good ground anywhere that two separate sections of the bike are near enough to allow it. Battery to frame obviously. Engine to frame. Headlight bucket to front forks. Front forks to frame. Etc.

[david]

ok Mr. Danger

Dave- thanks for your help so far.

well, i started your recomended tests.
know now that i'm an amature!! My father (and partner in this project) was a fighter pilot in WW2, and has a good grip on the mechanics. (he's impressed with the GS) anyhoo.

I pulled the main cable from the starter terminal,,, turned the key, and the fuse blew. I guess this tells me that the starter and relay may not be the problem. What would you recomend from here? i have concerns with the ignition switch.
I feel I could better explain via phone. If this is at all possible...
dbutler@team-psc.com

[J_C]

David, my father is my partner on my project bike too. Good luck to you guys!!

[david]

thanks!!
we need much of it.
Luck that is.....

[argonsagas]

Dave- thanks for your help so far.

well, i started your recomended tests.
know now that i'm an amature!! My father (and partner in this project) was a fighter pilot in WW2, and has a good grip on the mechanics. (he's impressed with the GS) anyhoo.

I pulled the main cable from the starter terminal,,, turned the key, and the fuse blew. I guess this tells me that the starter and relay may not be the problem. What would you recomend from here? i have concerns with the ignition switch.
I feel I could better explain via phone. If this is at all possible...
dbutler@team-psc.com

From this description it looks like only your starter has been removed from concern.

The easiest step to take next would be to check the solenoid/relay.

At the risk of insulting your intelligence, I will first explain how it works.


The system works by having a small current run from the starter switch to the relay, which energizes it. The relay/solenoid is nothing more than a switch that operates on electricity instead of having you move a handle to close internal contacts, and allow electricity to move between the in and out wires. (the heavy wires)

When energized magnetism is created and a metal plate moves inside the relay to close the contacts between the heavy wires running from the battery and to the starter.



The heavy wire has nothing to to with energizing the relay, so if it is disconnected, and you have the same problem as before, you have only removed the starter from your concerns.

You can check the solenoid by first disconnecting all wires from it.
Next, set your volt/ohmmeter to resistance. The setting is not important, but the lower numbers give a clearer picture.

Apply the leads to the large terminals on the solenoid. It doesn't matter which colour is used on which terminal.

Look at the meter and be sure it reads zero....no conductivity. If it shows any conductivity, you have an internal short and you need a new solenoid.


If no reading shows, move on.

Tape or otherwise fasten the leads securely to the large terminals on the solenoid.

Next, fasten a single spare wire from the small connector on the solenoid and run it up to the battery. Briefly touch the end of the wire to the battery positive post and you should immediately hear a clicking sound from the solenoid. That is caused by the metal parts moving inside the relay.

Simultaneously, your meter should show conductivity between the two large terminals.

If that works, your relay is OK.

All of this takes only a minute or two, but longer to explain in print.


Note....your battery should be charged before doing ANY tests on the electrical/charging system.

[david]

great!

one more bit of info...
I checked continuity in the starter button alone (works fine)
and also in the starter disconnect switch alone (works fine)

then hooked the continuity tester from the red wire going into fuse box, to the yellow green going into the starter relay. Then pressed the starter button and pulled the clutch... no continuity,,, but without touching either, and the ignition switch turned to a position, there's continuity. Bad ignition switch??

[DaveDanger]

David, I don't have my service manual here at my fingertips right this minute so I'll have to get to that at my shop and take a look and see what the wiring colors are that you're referring to. Maybe then I'll be able to suggest something fresh.