sensor id?
 

My 87-924 has a yellow wire that went no-were. Found the engine was not original. Just got my new engine shipped from the States. Not that there is an additional 6% on top of the 15% tax because it's German.

Anyway the new engine has this yellow wire attached to a sensor on the side of the oil pan. What's this for? The other engine just had a plate there and still ran. Well till it toasted the bearing #2!

I think you're talking about the oil level sender. Its a yellow wire which runs around from the front of the engine to the pass side of the oil pan. It attaches with a 3 bolt triangular piece.

Yes, that's what it is....it's turns the red light on in the dash when the oil is low.