1990 Transport Power Window Problem

I have a problem with my windows in that I can't isolate what is
going on. Both the driver's and the passenger's windows will not work. I have checked the motors directly by bypassing the switches and they will go up and down. But when I put the switches back in, the windows quit. I thought that the switch was bad and replaced it twice with the same results. I have not been able to get the schematics for this car, but similar GM cars seems to have the same wiring that I have in the Pontiac. What I don't understand further is that one of the wires to the motor seems to be always hot even though the schematics show that both wires to the motors should be running to ground.

I checked the switches from the drivers side with a multimeter and the
following is what I got:

Continuity Test with Pink (Hot) Wire

Pin Wire Color Door Left Switch Right Switch

Switch Position Down Neutral Up Down Neutral Up
1 Blue-White Right No No 1/2 No No Yes
2 Black Ground No No 1/2 No No No
3 Blue Left No No Yes No No No
4 Tan Right No No 1/2 Yes No No
5 Brown Left Yes Yes 1/2 Yes Yes Yes
6 Grey Unknown No No No No No No

Continuity Test with Ground Wire (black)

Switch Position Down Neutral Up Down Neutral Up
1 Blue-White Right Yes Yes Yes Yes Yes No
2 Black Ground Yes Yes Yes Yes Yes Yes
3 Blue Left Yes No No No No No
4 Tan Right Yes Yes Yes No Yes Yes
5 Brown Left 1/3 No Yes No No No
6 Grey Unknown No No No No No No


In my opinion of the schematics that I saw for the GM type car door, with both switches in the neutral position, the Brown wire should not have continuity with the pink wire, and should have continuity with the Ground wire. It is apparent that this is not happening. I can't believe that I had three bad switches.

Can anybody help me with this. It gets hot in texas, and we need to get
those windows open.

Thanks

Bob Hengstebeck

I had the same problem. All of the switches were good and I could get voltages on some of the wires.......Check the wires inside the boot that goes in between the door and the body of the van....You'll be amazed at how many wires will be broken.......Just by opening and closing the door!.......By the way...it's a really tight fit trying to get in there....good luck.

THis diagram for transport
www.avigex.ca/xport/pwrwindows.jpg