94 E320 wagon right tail light out
 

The bulb out indicator on the instrument panel came on, I figured change the bulb. Changing the bulb didn't fix it, I replaced the fuse (#8), I also cleaned the bulb socket terminals, the tail light is still out. Anybody have any ideas? If anybody could post a wiring diagram, I could trace it out.

Thanks,

J. Mullen

Ultimately the power is sent out by the lamp failure monitor control module. I have seen these fail to send out power, although in this case you shouldn't have the warning for that bulb being out. Proper way would be to check for power and ground at the socket. One thing I did for an owner who had this happen to one of the license plate bulbs was to jump the two wires together under the monitor, so had 2 bulbs powered by the one wire.
Gilly

Does anybody know where the lamp failure control module is located?

Read Manual
 

The owners manual of my 96 C220 says that if an exterior lamp fails, the lamp failure indicator at the dash will come starting at the time the exterior lamp is turned on. In your case, if all your exterior lights are on, it might be a module problem. But b4 going too far, I would make sure that in fact ALL your lamps do come on.

Tail light failure
 

I had this problem with my license plate lights. I install new bulbs and they worked only to go back to not working. The indicator light remain on when the bulbs stop working. To solve the problem I was having after weeks of seeing the intermittent indicator light on the desk coming on and off. I decided to fool around with the license plate lights and trace the wires. I pulled off all kind of stuff and had to cut open the wire insulation that incased the wires. I finally discovered that the wires running from the license plate bulbs had somehow broke apart. How that happen I will never know but it was cut clean in two. I assume that when the bulbs worked it was tapping the two cut wires and when the wires did not touch or spark the indicator light would come on suggesting a bulb was blown. Good luck on your hunt.

That module is in the rear part of the fuse box, IIRC you need to remove a few screws to get that rear cover off. Not 100% sure, but I think it's the real long relay, there are a few smaller modules and relays in there too. What would help the most is to get a wiring diagram for the exterior lights, would explain alot.
Gilly