http://community.webshots.com/myphotos?action=viewAllPhotos&albumID=552277097&security=awgQlF for pictures.
Sorry - I didn't get tinyurl to work for me.
When trying to diagnose problems:
1) If nothing happens, check the fuse. Number 23 for the 1990 Westy. But this is probably not the problem.
2) The most likely problem is broken wires in the harness between the door and the van body. There may very likely be a number of problems which may cause strange symptoms.
3) Another spot that may need to be looked at is the sliding switch which you the operator push or pull by using your key or the lock button which activates the motor.
2 and 3 means taking off the door panel. This is not difficult to do and can be done in a few minutes if you have done this procedure a few times. Can give details if anyone wants to know..
The black box that holds the switches and motor also can be taken apart fairly easily. This needs to be done to get at that sliding contact to check the 2 little springs. They are small and one or both may be rusted and broken.
What I found was a broken red wire(power) and brown wire(ground) in the driver door harness. In the passenger door harness, the yellow wire was completely broken and the white wire had cracked insulation.
Both the driver side and the passenger side controllers had broken springs under the sliding switch which may or may not have stopped it from making good contact.
This post may make it clear as mud to you. I hope the pictures will help. At least you can see what it looks like behind the panels.
If interested I can describe the current path that occurs as the motor cycles through its' locking or unlocking movement.
Ed Wiebe
1990 Westfalia
