Driver side rear power vent window will not close?

Hi,

I'm going to try and explain how this works. Basically, there are two wires going to the window motor (let's call them wire A and wire B). When you open the window, power is supplied by wire A and it returns to ground via wire B. When you close the window, power is supplied by wire B and returned via wire A. The only thing this does is reverse the polarity of power to cause the motor to work in opposite directions.

Now, power is supplied to the vent window switch via the body control module (BCM). If every other window is working properly, the issue is most likely a bad switch. Otherwise, there would fault with the operation of other windows that get power from the same supply. If one of the two wires at the motor was bad, the vent wouldn't open or close.

I attached the wiring schematic below, so you have a reference to what I'm saying.

If you want to check the power supply when the window should close, disconnect the window motor. Using a test light, probe the dark blue wire on one side of the tester and a known good ground on the opposite side. Have a helper actuate the window to close. My guess is there will be no power supplied. However, if you find something different, let me know. If there is no power, the driver's side switch will need to be replaced.

Here is a link you may find helpful:

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

Let me know what you find.

Joe

See pics below.