My wife came home this morning from the grocery store and said the left rear window wasn't working in the Yukon. I confirmed the issue and the left rear window is not working from the master or rear switch. I tested for power and ground at the rear switch, all okay, jumped power to motor both ways and the motor works fine. I tested all wires to the body connector at the B-pillar to make sure there were no broken wires in the door jam. I swapped rear door switches and same symptom occured. I removed the master switch and checked for obvious issues, but found nothing. Only other item to note is the service stability message came on yesterday as well, not sure if its related but I did have an issue last year where the passenger front window or lock wouldn't work and a stability message came on, it was a bcm fault and had to be reprogrammed at the dealer.

I guess the only thing I found when testing is on the switch connector, there are four large and four small wires, the larger being power and ground, and the other two to the motor, and the four small wires carry 12 volts on the passenger rear door and nothing on the left rear door where the issue is. Does this seem like a BCM fault again, or is it something else I should look for. Also does anyone have the schematic for the power window wiring so I can further track those four wires?

 

Hmmm, thats def. strange.

All is checking out except BCM, i guess a Tech II scanner is in order.

Going to move to Tuning, Diagnostics, Electronics, and Wiring - PerformanceTrucks.net Forums for better traffic / answers. Good luck.