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,

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1990 300SL-24
1993 C250D with a minor 600+k kilometer
www.MBenzNL.com(the Netherlands)