Accidently Reversed booster cables, now starter engages when key is in 'run' position

OK thanks. So it's likely back where I it's not easy to get at (in this case). Will need to tear the whole thing apart to get at it but glad we have an idea now.

Made a video showing what I've observed so far: https://youtu.be/twCNbZGTeW0

I suspect that when the jump was reversed it caused a backfeed of power through a wire that couldn't handle the amps and has now melted the wire from the key switch to whatever the L connects to to the wire going from the key switch to the small terminal on the starter solenoid. So I would be looking at the wiring harness for melted wires.

Disconnect the L wire from whatever it connects to on the mower, and the small wire at the starter solenoid. Now disconnect the wires connected at the key switch and take your ohm meter and put one lead on the S terminal wire at the key switch harness and the other lead on the L terminal of the key switch harness and see if you have continuity. Continuity means that they are most likely melted together. But what they are feeding needs to be disconnected to prevent a common ground from completing the circuit during the test. Also I would disconnect the battery while doing this test just to make sure something doesn't get crossed and cause other damage.

OK thanks very much ILENGINE. That's some good suggestions and I'll try that. I'll have to dismantle the machine a bit more to get at some of that. Thanks again to the others also for your suggestions. Great help of this forum. This is exactly what I was hoping for.

Diode in the kohler harness?

Luffydog said:

Diode in the kohler harness

Click to expand...

You were right. https://youtu.be/d7NCxM5TGEE

Thanks everyone to helped find this problem. Great forum and good guys. Cheers.

Did it start and run after you replaced the diode or harness? Glad you found the problem.

Still putting it all back together (had to yank the engine out). But so far with what I have back together, it's no longer cranking over in 'Run' and now only cranks over in 'Start'. Good sign but no, have not run it up yet. Hope to get to that later today or tomorrow. TNX

Sorry, forgot to update here. Confirmed that was the problem. Runs great, acts the way it's supposed to now. Thanks all for the help!