Windows: Description and Operation

Voltage is applied to the LH window from the Delayed Accessory Bus (DAB) Relay which feeds the PWR WDO Circuit Breaker (Refer to Delayed Accessory Bus (DAB) Relay, for a more detailed description). Accessory Delay Module

The Power Windows are driven by reversible permanent magnet motors. Each motor is controlled by two normally closed switches resting at voltage. When the RH Front Power Window UP Switch is in the "UP" position, the "UP" contacts of the switch are connected to ground and the motor runs to drive the window up. When the switch is released, the contacts return to their normal position and the motor wire is returned to voltage. The motor stops.

To lower the window, the DN Switch contacts are connected to ground. The polarity across the motor is reversed from the polarity that occurs when the UP Switch is pressed. The motor runs the opposite way to drive the window down. The LH window circuit operates in a similar manner, but also includes an auto down function. This function allows the driver's window to open fully by holding the DN Switch in the "DOWN" position for 300 ms. The LH Window Motor circuit is controlled by a Power Window Control Module. When the "UP" Switch is closed, a ground path and a signal are provided to the Power Window Control Module, and the Window Motor. When this ground signal is provided to the module, the module applies voltage to the motor, causing the motor to run in the "UP" direction. When the DN Switch is closed, a ground signal is provided to the module. With this ground signal provided, the Power Window Control Module provides a ground path for the Window Motor. Since voltage is applied through the "UP" contacts of the switch, the motor runs in the "DOWN" direction.

Each motor is protected by a built-in solid state circuit breaker. If a Window Switch is held on too long with the window obstructed or after the window is fully up or down, the circuit breaker opens the circuit. The circuit breaker resets automatically.