83 300SD door locks

[Frank hawley]

Auto has 255k doors lock but will not unlock on vacuum. When I turn key in drivers door I can hear what sounds like a reciprical pump running in the trunk on the passenger side (starboard for you sailors)for about 30 seconds. Just had flat and spare was used any vac lines in this well. Also piled 10 bags of mulch in trunk is there a vacuum tank under the rear window that could dislodge. Also recently had new passenger window crank motor installed. Would greatly appreciate your experience with similar problem.

[Tom Hanson]

Something very likely went haywire while installing the new window lift parts.

[GeorgeMurphy]

The door lock pump is located in the trunk on the right side of the spare tire well - it is under a metal bracket and encased in rubber. You may have knocked loose a vacuum line that operates the door locks . . .

[Frank hawley]

Tom and George
Thanks for your quick responces. George, you are correct, I found the pump and a disconnected line at the wye just behind the fuel door manual cable. This didn't solve the problem. I visited West Chester MB on another matter and their inspection showed the vacuum servo in passenger door had failed. They installed a new one while I waited.