Dead

[Clint]

After a clumsy refit of the stock air box on my '81 GS650G, it won't start. I tried everything to put it in without pulling the carbs (which is exactly what I should have done in the begining.) I removed the battery box, and I think I missed something in the reassymbly. I turn the key on and there is power to the head light. I put a test light on the yellow/green wire going to the starter relay and it lights with the starter button pushed. I put a jumper across the relay to test the solenoid and it works. I replaced the relay, and still dead when I turn the key and push the button. No click, nothin'.

There was a black/white wire coming from the wire harness with a terminal end, like a ground wire, that I had missed hooking up. I connected it to the battery ground, but nothing happenin'. I attached it to the ground side of the relay, and nothin' happenin'. I jumped across the relay one more time, and it started to burn that little black/white wire.

I don't know what else to do (except repair the burnt wire.) I'm afraid...

[reddirtrider]

OK, it's good that you have voltage to the relay when you hit the starter button, but voltage isn't what activates the relay - it's current. In order to get a current to the relay you need a ground path from the relay when the starter button is pushed.

I don't have a wiring diagram for your bike, but take a look at it and you should see there must be a ground path from your relay.

As for jumping across the relay and burning wires, I have no idea what pins you are jumping. If you attempt to jump the battery positive connection to any other connection than the starter side, you're going to push too much current through your ground wire and it will burn up.

[Bribird]

the black and white wire is a ground...it should ground to the frame and it should also hook up to the starter relay. Make sure you have all your grounds hooked up...like the main engine ground which goes from the back of the upper case to the neg side of the battery. I would do a jump across the solenoid big posts and make sure your starter turns over. If it does I would send power (12v+) to the yellow/green wires and verify the starter bumps again.

Do some more testing and post the results.
good luck

[Larry D]

Have you had the bike started before ?
Not to sound trivial, but, did you you pull in the clutch ? There's a cutout that won't allow the bike to be started without the clutch pulled in, unless it's been disabled.

[duaneage]

Clint and I are going to work this out on the phone saturday night. I have the same bike so no doubt we will get to the bottom of this.

[reddirtrider]

Methinks he would not have power on the yellow/green wire if he still needed to pull the clutch.

.

He has voltage present. If there's another switch on the low side he still won't have current until it's closed. You'd be correct if the safety switch is on the high side. I don't have a schematic, just going from theory.

[Steve]

Not to sound trivial, but, did you you pull in the clutch ? There's a cutout that won't allow the bike to be started without the clutch pulled in, unless it's been disabled.

I put a test light on the yellow/green wire going to the starter relay and it lights with the starter button pushed. ...

Methinks he would not have power on the yellow/green wire if he still needed to pull the clutch.

.

[Steve]

He has voltage present. If there's another switch on the low side he still won't have current until it's closed. You'd be correct if the safety switch is on the high side. I don't have a schematic, just going from theory.

Schematic shows power going from ingntion fuse to clutch switch, to kill switch, to starter button, to starter solenoid. If he has power to activate the solenoid and the solenoid is not moving, it could be a solenoid ground or just a bad solenoid.

.

[reddirtrider]

Schematic shows power going from ingntion fuse to clutch switch, to kill switch, to starter button, to starter solenoid. If he has power to activate the solenoid and the solenoid is not moving, it could be a solenoid ground or just a bad solenoid.

.

Ok, then it looks as if all of the safety stuff is on the high side. You're correct then that it's either the solenoid ground or the solenoid itself.

[rustybronco]

He melted the ground wire in the harness.
battery to engine ground cable disconnected/ loose/not properly grounded?

[reddirtrider]

He melted the ground wire in the harness.
battery to engine ground cable disconnected/ loose/not properly grounded?

Not sure how he did it. One sure way is to connect the battery positive terminal to it with jumpers.

The problem with doing electrical diagnosis over the net is you have no control, and little information as to what is really going on.

The solenoid is a very simple device. It's nothing more than a relay that connects the battery positive to the starter. The relay is activated by applying a voltage to the positive side of the coil and having a path to ground from the negative. The current is limited in this path by the internal resistance of the coil. It doesn't use a butt load of current, hence the negative side, or return to ground, isn't a heavy guage wire. The current path to the starter does draw a large current, thus the heavier guage wire.

Very simple, but easy to melt wires if they are jumpered incorrectly.

[Clint]

Thanks for all the advice guys. Turns out the mysterious ground that I burned is the ground for the relay coil. I had it in my head that the case of the relay grounded the coil, and as long as it was attached to the battery box it was grounded. I tried attaching that wire to every ground but the relay case. It's a good day...I learned something.