this is the overvoltage relay. It is behind the battery. You have to remove the plastic shroud to get to it. It has a red top and the fuse is under there. I'll bet you jumped the car off recently.

------------------
Benzmac:
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM