Re: Starter keeps running even with relay removed
It's a classic symptom of a stuck starter solenoid.
You can disconnect the big +12 cable from the solenoid, then connect the jumper cables again. If the key circuit is stuck closed, then you'll hear a big "click" from the solenoid when it engages. It won't start, as the solenoid cannot put current through the starter with the +12 cable disconnected. This will tell you if it's the solenoid (it doesn't "click") or the key circuit (it "clicks").