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

I have a Kohler Command CH23 on a Deines Mower. When boosting the mower, I accidentally reversed polarity when boosting it (stupid I know). While it was reversed (and didn't realize it), when turning the key, I could hear something like possibly the starter turning backwards (but not engaging the engine). Don't know if it actually was turning backwards, just sounded that way. I then realized my mistake and corrected the polarity of the booster cables. But now when I went to start it, I turn the key to 'run' and it starts cranking and continues to crank even when engine starts. Acts like a stuck solenoid (only, it's not stuck). Quickly shut it off. But every time I turn the key to the run position (not the start), the starter starts turning the engine. What do you think I may have damaged?

I checked my solenoid with a volt/ohm meter thinking it's stuck in engaged position but it's not. So when I turn the key to 'run', I can hear the solenoid engage and the starter will start turning the engine to start it. I also pulled the ignition switch off and checked it's continuity and it appears to be working properly.

Any thoughts as to what might be wrong? Please give good detail, I'm no mechanic. Thanks so much for any help.

check for damaged wiring, insulation burnt off, all locations & use electrical tape, make sure all connections are tight & secure. you may want to remove starter, for Safety first remove negative ground from battery, for inspection & bench test.

do not remove starter, let Rivets weigh in on your electrical issue.

It's a nightmare to take the start off; need to pull the engine, and not easy to do that either (whole machine needs to be dismantled. But will check for burned wiring or loose connections. (didn't see any damage on the wiring on initial inspection. Thanks.

I would say there is a one way diode in the harness that controls the flow in the kohler harness that when you made the mistake it made diode blow now when you turn the key it doesn't know which way for it to flow those are replaceable I would just get the kohler harness replaced as it might have other damage to it.

Sounds to me the relay is fried, stuck on.

The solenoid is good, I put a VOM on it and it's dis-engaging when it loses power (plus you can hear the loud click when it engages). I'm starting to think that yeah, it may be the diode. So need to pull the engine out I guess. Thanks guys.

Check the starter solenoid trigger wire for voltage and if it has voltage when the ignition is turned on then there is a short in that wire or a relay that energizes that wire is shorted.
It is a bit difficult to go any deeper without a wiring diagram.
I am assuming you have a piggy back solenoid on the starter.

meteors63 said:

The solenoid is good, I put a VOM on it and it's dis-engaging when it loses power (plus you can hear the loud click when it engages). I'm starting to think that yeah, it may be the diode. So need to pull the engine out I guess. Thanks guys.

Click to expand...

But it is only supposed to be energized when the key is in the start position. Sounds like you said it was energized when the key is in the run position.

bertsmobile1 said:

Check the starter solenoid trigger wire for voltage and if it has voltage when the ignition is turned on then there is a short in that wire or a relay that energizes that wire is shorted.
It is a bit difficult to go any deeper without a wiring diagram.
I am assuming you have a piggy back solenoid on the starter.

Click to expand...

Could not see any voltage on what I believe to be the 'trigger wire' (blue). That one eems to be grounded (or a continuity close to ground). By a piggy back solenoid, I assume you mean it's physically attached to the starter? If so, yes it is.

I've attached a wiring diagram.

helomech said:

But it is only supposed to be energized when the key is in the start position. Sounds like you said it was energized when the key is in the run position.

Click to expand...

Yes that's right. When I turn the key to the 'run' position, I hear the solenoid click to engage the starter. Pretty sure that's only supposed to happen when I turn the key to the 'start' position, not 'run'. When key is off, there is no continuity across the two large terminals at the solenoid so it does appear to be 'stuck' on.