just bought a 01 230 slk last night and noticed the rear view does not dim the side mirrors dim great but the rear view wont also am havig trouble with the dome light it will not come on no matter where the swicth is and the door open or not doea the same fuse supply power or is there somewhere else to look thanks john

 

Dome light uses the same power supply therefore presumably fuse. It is also a supply that has a X minutes limit on it for battery conservation (starting) purposes via the body controller.

On/Off control is via two different ground circuits dependent upon dome light switch position.
Route 1 is direct to ground.
Route 2 is via the PSE..i.e. door switches.

Hope this helps.
Stuart