Yeah, did a search, but still have questions. Does anyone have a hint as to what might be the fault in my 1983 W126 turbodiesel central locking. Symptoms are: trunk pump works for 45 sec. -which shows no or insufficient vacuum pump down. All lock buttons in doors are pushed (pressurized ?) in up position except driver door lock(I'm thinking that this showes the pump is building vacuum). Passenger door does not respond to key operation but driver door does. Trunk lock will respond to key. Fuel lock does nothing. Is there a electric switch in the driver door that controls the switch-over point from locking to unlocking that could be the problem? Something has to control the locks knowing to unlock/lock---where and what is it?

Many thanks,
Regards,

Run-em
1983 300SD--aka--SPARKY THE DIESEL