just bought a 1995 e320 and found passenger side backup light doesn't go on. when I openned tail light assembly I found bulb missing, but more so the contact and wire lead for that bulb position are missing too. there are total of 6 leads coming from the wire clip. compared it to drivers side tail light and found that one has 7 leads. I'm beginning to think P.O. replaced the wiring and right tail light assembly with same from a different year, perhaps due to collision repair? the dash "bulb" light goes on soon as I shift to reverse, so the car senses something should be there.
any helpful insight appreciated.
jack

the empty socket on the passenger side corresponds the rear fog light on the driver's side which is illuminated via turning the headlight switch fully clockwise then pulling it toward you. Do you have an owner's manual? Apparently a rear fog light on one side is though to be enough by the Eurpoeans (in the US we don't think any are necessary?). Likely MB's sold in Great Britain will have the ligh on the right and the empty socket on the left.
regards,
Mark

right on the money. thanks. problem turned out to be the obvious, bad bulb on drivers side.