W124 Drivers side door lock issue
 

On my '88 300TE when you lock the car with the key from the drivers side, it ONLY locks the drivers door, when you unlock from the drivers side w/ key it will unlock ALL the doors, but will not lock the others. When you lock or unlock w/key from the passenger side or tailgate it will lock and unlock all doors as they should. Does anyone have a clue what the problem might be with the drivers side? THX

It sounds like a problem with your driver's side vacuum door lock element. There is a 3 pin connector that plugs into the element. There are contacts in the element that signal the central lock pump when the lock is moved up or down. Aside from the element there is a possibility of harness problems in the door hinge but that is rare compared to vacuum element failure. I'd replace the element before any further diagnosis.

Ok, I am going to give that a try first. and report back with results...thanks for the tip.

THAT WAS IT !!!!
The element itself is okay, turns out it had become unplugged, put the plug back in and it works like a charm....Thanks for heading me in the right direction.

No problemo. After having my M/B totaled in a hit and run a bit ago I've been trying to get some good karma in the bank.