Radio turns on when I open door!!! Electical help please...
 

1986 300SDL is the car and I just got it. Some wierd stuff going on with the dome light circuit. Dome light functions as it should when door are closed but will not come on when the doors open and the radio comes on instead. The car has an aftermarket radio. Is it possible it was installed incorrectly? What is the correct wire to power the radio? Why are there two door switches on the door jamb?

Thanks for reading.

-Alex

radio comes on
 

behind the cluster there is a complex buzzer switch.there is a diode gone bad. replace the relay and all will be well.

david, do you mean the seatbelt hazard relay?

relay
 

no i mean the key buzzer relay.it is complex and does several things.you will find that the dome light probably comes on if you open the right front door and that virtually proves it.

Thanks for the tip. Do I have to remove the cluster to get at this relay? I hate to ask such a question but I don't want to replace the whong one! I'll order it from our host here if i can figure out the part #.

This forum is fantastic!!

-Alex

relay
 

you are going to have to remove lower panel under steering wheel[not an easy job lots of hidden screws]the warning module[mb name]hides near the top of brake pedal arm on the immediate left of it.

After looking at a lot of other threads here I think I found the problem!! The seat diode in the fuse box was cracked. I unplugged it and the problem stopped. I ordered a new one and I'll let you know how that goes. Beats tearing into the dash!!

-Alex