I just purchased a 1989 300 SEL

Weird thing with the seats.

Seats operate with the door open and keys out. Some functions are iffy (memory)

However, with the doors close and ignition on, the seat controls are dead. No adjustment, either side.

I know there is a feature to adjust the seats with the door open and I'm assuming there's some relay that makes that possible.

Any ideas what could cause this to happen?

Thanks,

Tim