I have a 1987 420SEL and my rear courtesy light no longer works using the panel switch. It still works OK when you open the doors. I have tested the switch and it works fine. I have also checked the terminal where the switch plugs into and it's working OK. This problem just happened all of a sudden.
Second question, could somebody tell me what the silver relays are for in the fuse box. They seem to be designated by a letter. Is there any way to tell what each individual relay is for?
Any info would be appreciated. Thanks!