Unplug the round wiring connector from the drivers door and scrape off any corrosion from both the male and female side of the connector. A paper clip is good for the female side. Be careful not to expand the female connectors or break them. Use a small flat object for the male pins. (tip of precision screw driver)
If this does not give you the contact you need to operate the door lock... open the wiring harness that is under the floor carpet behind the front passengers seat located about where the right rear passenger would place their feet.
To do so take a flat bar and pop up the right back door sill so that you can lift the carpet. You will see a chanell with wiring inside. Cut open the (correct) harness to expose the wires for the central locking system. Check the crimp connectors on the red wires with white stripe (about 5 are crimped together at that location) and the brown wires that are crimped together along with the brown wires with black stripe that are crimpted together. These are the hot wires, the switched ground wires and the ground wires respectively for the central locking system. You can trace the red/white stripe wire from the vacume pump that is located under the back seat so that you will open the right harness.
Make sure that the connections are not corroded. I would solder them after cleaning them up. They often corrode under the rug from wetness or dampness from open window, sunroof etc.
If this does not do the trick say a prayer to St. Anthony who is the patron saint for lost causes.
PS Make sure that the vacume line to the driver's door is not detached, cracked or broken. Check this out while you are cleaning the contacts for the door's electrical connector.
Also, to remove round electrical connector... press the black tab on the socket and pull straight out. Note location of squared off side of plug so that you can position it correctly when you are ready to plug it back in again.
[Edited by ejsharp on 05-31-2001 at 03:21 PM]
1993 190E 2.3
2000 Toyota 4x4 Tundra