THe dome light,memory seat dont work when I open the driver door.I have read threads about seat belt relay.Is there a way to find out if it is in deed the relay or a broken wire from the relay to the driver door switch?The door switch is ok.91 420sel

First best bet is to check fuses. there should be a label as to which ones affect those... If it looks good take it out and make sure it's not a hairline crack (infamous) before you spend too much time on anything else.

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html