560SL burned out bulb idiot light

[Johnhazen]

I have tracked the problem down to the passenger side rear marker light(red light on the side of the car). I do NOT have voltage to the green white wire that powers that bulb. The bulb is good and the socket is good. I can get it to light up by jumpering from the rear tail light. (don't do this too long, it burns out the fuse, ask me how I know). I recently had the head light switch replaced. I am wondering if they forgot to attach a wire to it and if that might be why I do not have voltage to this passenger side rear marker light. Jumpering the light does NOT cause the idiot light to go out, presumeably because the idiot light "system" is seeing an open connection on the wire feeding that light from up front somewhere. I have cleaned the two sockets that attach to that assembly, so I doubt that they are the problem. They looked clean to begin with, but I hit them with WD40 anyhow.

[Johnhazen]

I have now noticed that the light works in the morning when it is cooler. Can anyone tell me if there is a direct wire going from the headlight switch to the rear passenger side marker light? I am thinking maybe the connection is loose since I just had a new headlight switch installed.

[compu_85]

The wire goes from the headlight switch, to the lamp monitor relay, to the rear light. I believe the fuse is between the relay and the light.

My lamp monitor relay had some cracked solder joints, a quick reflow brought it back to life.

-J