Power window wiring

Help...working on a 1981 GMC Cabellero. Passenger side power window inop (drivers side has a mis-match door with manual window)

Took my meter, hooked ground to body, and probed the connector to the motor. I had 12v using the switch going both up and down. So I figured it had to be the motor.

Replaced motor and it still doesn't work.

Should have realized I was using a different ground than what was being supplied to the motor.

I can use a jumper and put a good body ground to the switch, hit it, and the motor works.

So, I have a bad ground going to the motor.

My question is, where is this ground coming from? I found wiring diagrams for this car, but nothing showed the power window system.

Could it be a bad switch? Keep in mind using a separate ground, the 12+ switches on and off just fine, but using the ground at the plug at the motor, it does not.

Anyone have a wiring diagram for this car that shows the power windows? Or has someone come across the same problem? Is there some sort of relay or something under the dash that switch runs through?


2nd unrelated question......are the wiper arms on this car interchangeable from left to right? I need a replacement on the passenger side, but I can only find a part number for a driver's side.

Thanks for the diagram.

On the switch, there are 5 wires on it. Tan, brown, 2 blue wires, and red.

I dont see the brown wire in this diagram. Could this be the ground?

Also, the diagram does not show which wire is ground.

And the master control switch is not hooked up. I wonder if this affects anything?

Are we 100 percent sure the motor grounds to the body? Must be different on my 81 Cabellero.

Thats what I originally thought. I tested 3 different motors by grounding the body, and putting 12+ to each terminal, and nothing, on ALL 3 MOTORS. 2 new and 1 old.

So, I tried putting negative on 1 terminal and positive on the other terminal, and it worked. Switched polarity and it reversed.

So somehow the switch sends pos and neg to the motor, and reverses polarity.

Ok, I downloaded a 85 monte wiring diagram and found one that is like mine. The ground comes from the master switch in the left door.

Problem is, previous owner replaced the drivers door with a manual window, so the switch is not there anymore. Looks like it needs that ground, or possibly the whole switch, to operate.

Can anyone think of a way to wire it without the switch?

This is the diagram that looks like mine

http://www.badss.net/other/monte_85_wiring.pdf

I found the wiring, and grounded the wire. Still not working. I guess I need the master switch for it to work.