GM Service Manual Online
For 1990-2009 cars only

Power Windows System Components

The power window system consists of the following components:

    • Driver window switch
    • Passenger window switch
    • LR window switch
    • RR window switch
    • Up relays in each of the window switches
    • Down relays in each of the window switches
    • Window motors in each of the doors
    • PWR WNDW 30A Fuse

Power Windows System Controls

The power windows system can be controlled by pressing or pulling the appropriate power window switch.

Driver Window Operation

The driver window switch is supplied battery voltage through 30A fuse in the underhood fuse block. The driver window switch UP and DOWN relays controls power and ground to the window motor through the motor control circuits. The driver window switch relays can be energized by the integrated rocker switch. While the driver window switch is in an inactive state, both of the window motor control circuits are grounded through the UP and DOWN relays. When an UP or DOWN relay is energized, the battery supply circuit is closed to the corresponding motor control circuit while the other control circuit remains grounded through the de-energized relay. The supply side of the UP and DOWN relays receives voltage through the PWR WNDW fuse.

Express Down Feature

The drivers window has an express-down feature that allows the window to be lowered fully without continuously holding the switch. Pressing the front of the switch past the first position will activate the express-down mode. The express-down mode can be canceled at any time by pulling up on the switch.

Lockout Switch Feature

The window lockout switch, when closed, provides power to the passenger door switches enabling normal switch window operation and when the lockout switch is open, power is cut to the passenger door switches disabling window switch operation. Normal window operation is still available from the driver master control.

Passenger Window Operation

The passenger door window switches are supplied battery voltage through 30A fuse in the underhood fuse block. The door window switch UP and DOWN relays controls power and ground to the window motors through the motor control circuits. The window switch relays can be energized by the integrated rocker switch. While a window switch is in an inactive state, both of the window motor control circuits are grounded through the UP and DOWN relays. When an UP or DOWN relay is energized the battery supply circuit is closed to the corresponding motor control circuit while the other control circuit remains grounded through the de-energized relay. The supply side of the UP and DOWN relays receives voltage through the LT PWR WNDW or RT PWR WNDW fuse.

The driver master control also contains switches which will give the driver control over the right front, left rear and right rear passenger windows from the driver position. When the appropriate master control switch is pressed, the UP or DOWN relays within the passenger door window switch will be supplied a low reference circuit from the driver window switch, thus allowing current to energize the appropriate relay and causing the window motor to function in the same manner as when the passenger door window switch is pressed. The window switches on the driver master control also have 2 positions; UP and DOWN, their position is a direct input into the driver window switch.