My 300SD 1985 is having some problem with the electrics.
1. When I open the rear door partially, the inside rear light comes on, but as soon as the door is opened wider this light goes off and the right rear reading light comes on.
2. The light near the inside rearview mirror only works with the switch and will not shut off when the front doors are closed.
3. The light in the bottom of the front passenger door remains on when the door is closed, and goes off when the door is opened. This light remains on even when the ignition is off.

Any help or advice will be most welcome.

Thanks.

Due to the age of the car and that all of your problems can be deduced to your doors I would start by measuring the contacts in the doors (the ones that among others trigger the light to go on.) If you find any contact problems in them you should start by spraying them with some kind of anti-oxide-spray/fluid. The contacts can easy be affected by oxide because of their vulnerable position.

1985 300SD...these cars have front courtesy lights similar to the ones used in the W124.?.? You probably have a bad switch in the front courtesy light that causes the problem there. The front entrance lights are powered through the front courtesy light...Two problems, one solution (repairing the switch or exchanging the light).

The problem in the back is probably caused by the door contact...

...just some thoughts...

greetingz,

Thanks for your replies.
After reading through older communications on the subject, I cleaned all the fuse contacts and put back the fuses and this seems to have cured the problems for the moment.