Passenger Side Power Window

RFULTZ

MEMBER
1988 CHEVROLET SILVERADO

Electrical problem V8 Two Wheel Drive Automatic 43000 miles

Passenger side window will not go down. I took the motor out of the door and jumped it off of a battery and it worked in both diections just fine. I plugged it back up and it will go up from the switch on the driver side and the passenger side, but would not go down. I tested the wire lead that plugs into the motor with a test light. On the down side of the lead I get a light when I push down on the switch. On the up side of the lead I get a light when I push up on the switch. When the lead is plugged into the motor the motor will do nothing when I push down on the switch but works fine when I push up on the switch. I'm pretty sure this is a ground problem but do not know where to start looking. Also I have removed all switches and put them on the driver window switch location and they all work fine on the driver window so this rules out the switches. THANKS

2 Replies

JACOBANDNICKOLAS

MECHANIC
109,755 POSTS

The power to the motor is doing what it should. Basically, the motor is grounded through the switch which reverses polarity. If I had to guess, I would say that you have a bad switch. I realize it supplies power to a test light, but when the load of the motor is on it, I think it can't handle it. Now keep in mind, I realize that this happens with both door switches, but the driver's door should be the problem. You could try putting a load on the switch to see how many amps it produces under a load.

Here is a guide that shows how to test it

https://www.2carpros.com/articles/electric-window-repair

and

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Here is a power window wiring diagram so you can test the wires as well (below)

https://www.2carpros.com/articles/how-to-check-wiring

Let me know if you have other questions.

Joe

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