Starter turns in glow position 190d

[hornigio]

Here's an odd one... while testing my glow plug relay, with the key on in the glow position, the starter suddenly started turning and cranking the engine. It's a 1985 190d.

I shut everything off quickly, but now the starter cranks when in glow plug position. It will start, but the starter keeps cranking all the time. Of course, I can't run it this way.

Did I fry something? there were no sparks or anything out of the ordinary during my tests. I tried completely disconnecting the glow plug relay, but it still cranks when the key is in glow position.

Is this a bad ignition switch? If so, how do I replace? Where do I find a wiring diagram? Is there another relay somewhere that could be the culprit? Thanks!!!