HI-
I'm about to pull the trigger on a 1987 420 SEL in great condition, EXCEPT for an odd electrical problem..... the mechanic I am buying from is going to fix it, but I thought I would try and get some feedback here regardless and in case it is indicitive of a greater problem. Hopefully not.

The automatic seat controls on each door, only work when the doors are OPEN! Any idea what this could mean?
I have checked the car thoroughly and this seems to be the only electrical problem.

thanks in advance
Jim

 

hi,
Not sure if it applies to a MB model as old as 87 but most modern MB's have a convenience feature whereby the seats operate with the doors open.
....In case you can't get into the seat and shut the door due to a small person having driven the car before you. Also for showroom condition demonstration.

The power to the seats is supplied through a relay activated when the doors are open. By an ECU on later cars..
Looks like your problem is the power supply thru the alternative "ignition" controlled route.which is via a different relay / fuse etc.

Stuart.

 

Cool, thanks Stuart.
Excuse my ignorance, but how does something like this "happen" ?
Is it indicitive of greater problems that might exist? I realize its an old car and this stuff will continue to happen.

thanks
J

 

Whatever make/model, electrics are usually the most troublesome.

Connections become loose, or corrode due to moisture. Likewise switch and relay contacts.

Newer vehicles are more troublesome because they use digital electrics and connection problems on this digital highway can cause the strangest things to happen. i.e. Turn on the radio and the headlamps come on etc etc etc.

Think yourself luchy that your car is before the digital age.

Stuart