1992 300E - I have one license plate lamp that works. The other socket has a valid ground but no +12V.
I have the trunk lining off and upon inspecting the the wiring I see it quickly goes off into the shrouded black yonder. I don't see any visible damage to the wiring loom at obvious spots.
Rather than track down where the wire is broken (I have no idea how to do this if it is inside the body work somewhere), I am wondering about just stealing power from the other lamp. This will obviously light the lamp, but will not turn off the warning light on the dash.
I really am not concerned about being warned if just one of my license plate lamps is working, and wondering if I could hack the wiring so that the warning light will go off if either lamp is working.
Looking at the wiring diagram (above), can I just short the two wires going into the Lamp Failure Monitoring Unit? Or will this give an incorrect resistance reading or something and cause the failure warning to still come on?
If this is a bad idea, alternate suggestions or hints at tracking down the break instead are appreciated.
If it seems like a good idea, I'd appreciate a pointer from someone who knows where the Lamp Failure Monitoring Unit is located.