Operation CHARM: Car repair manuals for everyone.

How the Circuit Works

Power Windows

How the Circuit Works

CAUTION: Disconnect the window switch connector before you start. You could unintentionally switch the window to "automatic down" while working in the driver's door with the power on. The moving glass could injure your arms, hands, or fingers.

Battery voltage is applied at all times to the contacts of the power window relay. Fuses 24, 25, and 26 (in the under-dash fuse/relay box) receive voltage through the power window relay when the relay is closed. These three fuses supply battery voltage to the left rear, right front, and right rear window motors.

Fuse 27 in the under-dash fuse/relay box is hot at all times and supplies battery voltage to the door multiplex control unit, and to the LED's in the power window master switch.

The power windows have a key-off delay function. The windows will still operate for up to 10 minutes after the ignition is turned off. Opening either front door will cancel the delay function.

Reversible electric motors drive the power windows. Each motor is protected by a non-serviceable built-in circuit breaker. The circuit breaker will reset automatically as it cools.

Driver's Window

The driver's power window master switch is part of the door multiplex control unit. When you hold the driver's window switch in the UP or DOWN position, the door multiplex control unit applies power and ground to the driver's window motor in the direction requested.

Auto Down

The driver's window is equipped with an AUTO DOWN feature. When you push the window switch firmly down, the door multiplex control unit applies power to the driver's window motor. As the window moves down, the pulser in the driver's window motor sends a pulsing signal to the door multiplex control unit. When the window reaches the fully down position, the pulsing signal stops and the door multiplex control unit removes power from the motor.

All Passenger Windows

All windows can be opened and closed from the driver's power window master switch. The passenger windows can be also disabled from the master switch. When the main switch is open, voltage is not provided to the passenger window switches.

Left Rear Window

The left rear window switch receives voltage through fuse 24 (in the under-dash fuse/relay box). This switch contains two relays and an UP/DOWN switch. When you press the left rear window UP/DOWN switch, the corresponding relay energizes, and applies voltage to one terminal of the window motor. The other terminal is grounded through the resting relay contacts.

When you open or close the left rear window from the power window master switch, the door multiplex control unit sends signals to the relays within the left rear power window switch.

Right Rear Window

The right rear window switch receives voltage through fuse 25 (in the under-dash fuse/relay box). This switch contains two relays and an UP/DOWN switch. When you press the right rear window UP/DOWN switch, the corresponding relay energizes, and applies voltage to one terminal of the window motor. The other terminal is grounded through the resting relay contacts.

When you open or close the right rear window from the power window master switch, the door multiplex control unit sends signals to the relays within the right rear power window switch.

Right Front Window

The right front window switch receives voltage through fuse 26 (in the under-dash fuse/relay box). This switch contains two relays and an UP/DOWN switch. When you press the right front window UP/DOWN switch, the corresponding relay energizes, and applies voltage to one terminal of the window motor. The other terminal is grounded through the resting relay contacts.

When you open or close the right front window from the power window master switch, the door multiplex control unit sends signals to the relays within the right rear power window switch.