Starter stays running after key is released

[CorvallisBMW]

The starter is acting up. After I let go of the key the solenoid de-energizes and pulls away from the flywheel but the starter motor keeps spinning. I've confirmed the larger black wire that signals the starter to run is shutting off after I release the key but somehow, someway, the terminal that it connects too is staying energized (maybe from a loose or crossed wire inside the unit itself???) The smaller black/green wire that triggers the solenoid seems to be working properly and shows 0V after I release the key. I can get it to stop running by disconnecting the starter's power lead at the positive battery terminal once the engine is running, but obviously this isn't an optimal solution. Looking for some help here, wiring and electronics are all Greek to me :/

[weaksauce]

ignition switch going bad?

[CorvallisBMW]

I thought about that, but if it were a bad switch I think the wire would stay live after the key release. Right now the wire is going to 0V (checked by removing it from the starter and checking with a meter) on release but the terminal on the starter it connects to stays live with 12V (again, checked with wire disconnected with meter). Still a possibility though, I've seen wierder shit.

[CorvallisBMW]

Priced re-mfg'd starter at $155. I'd rather not spend the money and time to change the damn thing out, it's not gonna be easy.

[weaksauce]

i have 3 spare m30 starters. you want to borrow one to try and see if that fixes it?

[CorvallisBMW]

I finally figured it out. After replacing the starter with a re manufactured Bosch unit, and the problem still being there, I was fucking pissed. $150 I didn't need to spend. So I just started pulling off wires until something changed. I tried pulling the large black wire, thinking this would kill the power to the starter. It didn't. WTF? So then i pull the large red wire off. Starter stops. I'm thinking to myself, 'ok, so no that it was no power, if I shut off the motor and try to start it again i'll get nothing'. SO I turn the car off and go to start it again. Fires right up. I don't know exactly what that large red wire is, but it's fucking useless. I wrapped the end up with electrical tape and shoved it up under the manifold. It's just sitting there, the car is starting perfectly, I'm happy.