My daughter's '93 240 Classic has a problem with the central locking system. When you put the key in the driver's door lock, you can neither lock or unlock that door. If you turn the key a little, you can hear the motor actuators in the other three doors activate. The dome light also does not work (the bulb is good) and when you leave the key in the ignition and open the driver's door, the "warning chime" does not activate as it should. I checked the door switch for continuity when closed and open circuit when open and that checks out with a meter. I did a general search and found one reference to this problem, but only a description and one reply which said the original question was posted on the wrong forum (AWD) and to search the RWD forum. I tried that but did not find what I was looking for. I would appreciate it if someone could point me either in the direction of the post that covers this issue, or if someone knows what the problem is.

Thanks in advance.