On my '01 SL600 the interior lights that come on when you open the doors do not turn on. All the bulbs are good, actually replaced those as a start. I hear a relay clicking behind the fuse box when I manually operate the switch in the door jamb. Could this be bad or is there an another module that controls interior lighting. Also when I close the door after driving at night the fog lamps light up for a few seconds then turn off, I wonder if they are on the same circuit.

 

check the fuse box in the trunk

 

Might be too obvious, but sometimes the door switch is bad.

 

All fuses in back are good, also checked the switches with a meter and tested good.

 

The circuits are very simple. A fuse feeds one side of the lamps, while the other side of the lamps grounds through the switch in the door jamb.

A complete set of schematics is part of the comprehensive R129 Tech DVD available from 1-800-FOR-MERC for about $70. Or you can essentially browse the content of the DVD at www.startekinfo.com. The cost is $18 for 24 hours of access.

 

thanks for the heads up, dvd is probably a good investment...