It is located behind the left kick panel on the drivers side. Also there is a diode located on a small black box somewhere near or inside of the fuse box. This is most likely your problem. I looked in the CD-ROM and it did not give a location, but it did show the diode if the car had power seats as a option.
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM