Windows: Description and Operation

Power Windows

How the Circuit Works

CAUTION: You could injure your arms, hands, or fingers if you unintentionally switch the driver's window to "automatic down" while working in that door with the power on. Disconnect the window switch connector or the battery when working in the driver's door.

System Description
The operation of the power windows is controlled by the main switch in the power window master switch. When the main switch is in OFF, only the driver's door window can be opened or closed. With the main switch ON, all windows can be opened or closed either by switches in the master panel, or switches in the doors. The driver's window switch also has an automatic down mode which is turned on by holding the switch down momentarily.

The power windows are driven by reversible motors. Each motor is protected by a built-in circuit breaker If the 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 as it cools.

Driver's Window
With the ignition switch in ON, voltage is provided to the coil of the power window relay through fuse 6 (in the under-dash fuse/relay box). The contacts of the power window relay close, and voltage is applied to the driver's switch. When you push the power window master switch to UP, voltage is applied to the driver's power window motor (The motor's ground path is back through the power window master switch.) The driver's power window motor then drives the window up. When you push the switch to DOWN, voltage is applied in the opposite direction and the motor drives the window down.

Auto Down
With the ignition switch in ON or START voltage is applied to the coil of the power window relay. The contacts of the power window relay close and voltage is applied to the power window master switch. When you hold the driver's switch down momentarily, voltage is applied through the driver's switch to the driver's window motor. The control unit receives pulses at the pulser input while the motor is running. When the window is fully down, the motor stops, and pulses are no longer generated by the pulser. This is sensed by the control unit at the pulser input, and voltage is no longer applied to the driver's window motor.

Auto Up
With the ignition switch in ON or START voltage is applied to the coil of the power window relay. The contacts of the power window relay close and voltage is applied to the power window master switch. When you hold the driver's switch up momentarily, voltage is applied through the driver's switch to the driver's window motor. The control unit receives pulses at the pulser input while the motor is running. When the window is fully up, the motor stops, and pulses are no longer generated by the pulser. This is sensed by the control unit at the pulser input, and voltage is no longer applied to the driver's window motor

Passenger Windows
With the ignition switch in ON, voltage is applied to the coil of the power window relay through fuse 6 (in the under-dash fuse/relay box). The contacts of the power window relay then close, applying voltage to the individual window switches and the power window master switch. With the master panel main switch ON, the passenger windows can be operated from the individual window switches or from the master panel switches.

When you push the front passenger's window switch to UP, voltage is applied to the front passenger's window motor. (The motor is grounded through the contacts in the front passenger's window switch and the power window master switch.) The window moves up as long as you hold the switch in the UP position. If you push the switch to DOWN, voltage is applied in the opposite direction to the front passenger's window motor, and the window moves down as long as you hold the switch in the DOWN position. The window switches in the other doors operate similarly.

When you push the front passenger's switch in the master panel to UP voltage is applied through the front passenger's window switch contacts to the front passenger's window motor (The motor is grounded through the contacts in the front passenger's window switch and the power window master switch.) The window moves up as long as you hold the switch in the UP position. If you push the switch to DOWN, voltage is applied in the opposite direction to the front passenger's window motor and the window moves down as long as you hold the switch in the DOWN position. The other passenger window switches in the master panel operate similarly.