Operation CHARM: Car repair manuals for everyone.

Power Windows

With the Ignition Switch in the "RUN" position, voltage from Circuit Breaker #2 is applied to the Master Side Window Switch through CKT 341 and the individual Side Window Switches through a "Side Window Lockout Switch" that connects CKT 1307 and CKT 341. The Side Window Regulator Motors and Side Window Switches receive ground through the Master Side Window Switch, which is grounded at G200. When a window other than the LH Front Window is operated from the Master Side Window Switch, battery voltage will be sent to the Side Window Regulator Motor through the individual Side Window Switch. The LH Front Window is operated directly from the Master Side Window Switch.

The Power Windows are driven by reversible, permanent magnet motors. Each motor is controlled by a set of two switches, which are normally closed to ground. When any Side Window Switch is moved to the "UP" position, the "UP" switch will provide battery voltage to the Side Window Regulator Motor through the DK BLU wire. The Side Window Regulator Motor will receive ground through the BRN wire, the "DN" switch, and the Master Side Window Switch and drive the window up. When the switch is released, the switch contacts will return to their normal grounded position.

To lower the window, the "DN" switch will connect the BRN wire to battery voltage. Ground will be provided to the DK BLU wire through the "UP" switch and the Master Side Window Switch. The polarity across the motor will be reversed, causing the motor to rotate in the opposite direction and lower the window.

The Power Windows System also includes an Express Down Feature for the LH Front Window. This allows the LH Front Window to open fully when the LH Front Side Window Switch is pressed momentarily. All of the solid state circuitry controlling this feature is contained within the Master Side Window Switch.

Each motor is protected by an Electronic Circuit Breaker (ECB). If a Side Window Switch is held in the "UP" or "DN" position too long with the window obstructed, or after the window is fully up or down, the ECB will increase its resistance. By increasing its resistance, the ECB will prevent the side Window Regulator Motor from overloading. The ECB will reset to normal resistance when voltage to the Side Window Regulator Motor is interrupted.