GM Service Manual Online
For 1990-2009 cars only

The rear quarter window switch is on the interior lamp and multi-function switch. This switch allows you to open and close the LH and RH rear quarter windows. The battery voltage is applied to the rear quarter window switch when the ignition switch is in the RUN position through the PWR QTR VENT Fuse 10A, circuit 743. Voltage is applied to the quarter window actuators through circuit 902 when the open position is pressed. The quarter window actuators are grounded through circuit 901, the close contact in the rear quarter window switch, circuit 650 and ground G302. The motor runs to drive the rear quarter windows open. Battery voltage is applied to the motor in the opposite direction when the close position is pressed, circuit 901. The window motor is grounded through circuit 902 and the open contact in the rear quarter window switch, circuit 650 and ground G302. This closes the rear quarter windows.