I have a 1990 300D with 120K. When I put down the door lock from inside the car,on the drivers door, all the doors lock but will not open for about 40 secs. There is a hum from the right rear door, and none of the doors can be opened from the inside till the hum stops. Then they can be opened, and all the door locks open when the drivers door is opened. I have a hunch it is something to do with the vaccuum system...but please help as it is a very dangerous situation not to be able to get out of the car for this time that the locks inoperable.
Thanks for any advice......RSL007

It sounds like you have a vacuum leak. The hum is probably the vacuum pump which is in the vicinity of the right rear door but under the seat, or it is a audible leak inside the door at the actuator. If the locking system is losing vacuum, the actuators may take forever to complete locking and unlocking cycles. I would start by checking the right rear actuator for leaks. Start with a visible inspection of the hose, fittings, etc. Then apply a known good vacuum source and observe for function. The pump is probably OK, but it's not able to compensate for the size of the leak.

__________________
Jeff Lawrence
1989 300e
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.