Killswitch starts bike; Constant power to starter

Hello folks.

I noticed an issue toward the end of the season last year in that my bike would start when I turned the killswitch to run. I do not have to push the start button. Some other issues prevented me from handling that and now that I have the tank off I am looking for solutions.

Symptoms:
Killswitch engages starter motor.
Starter motor runs while bike is running.

I've opened up the control unit to check wiring. Everything seems to be ok in the control unit. The contact point from where the start button touches the metal to start the bike had some discoloration but seemed ok. Side note - The spring is a PITA to put back together once its out! I sprayed some WD40 into the control and when I started the bike up it blew the main fuse. Hoping that WD40 had some time to dry out and will try again today.

I checked wiring from the control down to the connectors. No visible issues. the wires split off and go all over the place down there so hard to tell which one I am tracing sometimes.

Ultimately the black and the black/yellow end up at the starter solenoid. If I unplug the solenoid, no power to starter engine as expected. One time I unplugged them both (black and black/yellow) and when I put back together the issue was gone but came back almost immediately.

The manual says I should be getting the same battery current at the Solenoid. I am not, its roughly 8v while my battery is 12v. Not sure if that would cause the issue I am having though. I found a solenoid online for about $10 so as long as there no soldering involved, is it an easy replacement?

I unplugged the starter motor and heard the click from the solenoid. The manual says that indicates that it is working.

I'm really trying everything I can think of before pulling that harness and replacing the control unit because there are about 4-5 splices off that going to other electrical parts, I don't want to start down the electrical rabbit hole.

Any ideas?

So this was a new problem last year and the start button & kill switch were working fine beforehand? just making sure this isn't a new aftermarket switch that never worked right.

Sounds to me like your issue will either be in the switchgear or where it joins the loom. Those kill switches are notorious for issues. For power to be getting to the starter motor you have a short at the kill switch although your starter button would also need to be sticking assuming the internal wiring is correct.
Check the kill switch for continuity in both the run and off positions. Also check for continuity of the starter button in both the live and off positions. Unless they are only live when in the run and live posistions you have found your cause. Then trace back your wiring untill you find the culprit.

Where is the black wire of starter Solenoid pluged into the main wiring harness, (wire colour)?
Some pics would help.

Warren3200gt wrote: Sounds to me like your issue will either be in the switchgear or where it joins the loom. Those kill switches are notorious for issues. For power to be getting to the starter motor you have a short at the kill switch although your starter button would also need to be sticking assuming the internal wiring is correct.
Check the kill switch for continuity in both the run and off positions. Also check for continuity of the starter button in both the live and off positions. Unless they are only live when in the run and live posistions you have found your cause. Then trace back your wiring untill you find the culprit.

New to electrical problems, mechanical problems that I can SEE are so much easier to spot. I'll google but what is "checking continuity"?

Yes this is an old control that has worked properly in the past. I first noticed the issue late last season.

I would love to get some pics, but the clearances are so tight. I barely have room to plug/unplug the wires to/from the starter solenoid. The black and black/yellow wires are going to the solenoid. They connect to black and black/yellow wires coming from the wiring harness.

I should mention also my bike has green Dyna ignition.

I should also mention that since I sprayed WD40 into the control (Some other spots online said it might help) that now the bike will not crank at all...as soon as I turn the control to run it blows the 20v fuse coming off the positive battery terminal.

First you need to find why you are blowing fuses. I suspect you have pinched a live wire against the handlebars when replacing the switchgear after your inspection and you have broken the insulation so that it is continually earthed and shorting out.
A continuity test is performed by placing voltage across the chosen path/switch. If electrical flow is inhibited by broken wires, damaged components, or excessive resistance, the circuit is "open" or in the case of a switch in the off position.
If electrical flow is allowed then the circuit is "closed" or in the case of a switch in the on position.
If you dont have a multimeter rig up a simple circuit tester using a bulb and two wires.