I tried searching "won't stop" but could not find my answer, so I apologize for asking if it has already been asked.

I have lots of experience keeping old cars going, but this is my first car other than just a Ford or Chevy. It is an 81 240D. I've had it a couple of months and it came time to change the oil. All went well, except after that the key will no longer kill the engine.

I found the stop lever, so I'm still not afoot, but I can't shut off the engine with the key.

Thanks ahead of time to anyone who might can tell me what circuit to run down.

Joe