Windows: Description and Operation
Battery voltage is applied at all times to the left front door power window switch through fuse C-18 and to the power window relay through circuit breaker C/B-2. With the ignition switch in ON or START, battery voltage is applied to the power window relay through fuse C-4. The power window relay energizes and applies battery voltage through the circuit breaker to all the door power window switches.Left Front Window
When you move the left front power window switch to UP, a signal is sent to the control unit. The control unit grounds the coil of the "up" relay. The contacts of the relay close, and voltage is applied to the left front power window motor. The motor then drives the window up as long as you hold the switch up. The motor is grounded through the open contacts of the "down" relay. When you move the switch to DOWN, a signal is sent to the control unit. The control unit then grounds the coil of the "down" relay, the contacts of the relay close, and voltage is applied to the motor. The motor then drives the window down as long as you hold the switch. The motor is grounded through the open contacts of the "up" relay.
Auto Down
When you move the left front power window switch to AUTO, a signal is sent to the control unit. The control unit grounds the coil of the "down" relay, the contacts of the relay close, and voltage is applied to the left front power window motor. The control unit keeps the relay energized until the motor drives the window to the fully open position. The motor is grounded through the open contacts of the "down" relay.
Passenger's Window
The passenger windows can be operated from the left front door power window switch or the respective door power window switch. The passenger's door power window switches can only operate the windows when the lock switch in the left front power window switch is in the OFF position.
When you move a passenger's door power window switch to UP, a signal is sent to the respective control unit. The control unit grounds the coil of the "up" relay, the contacts of the relay close, and voltage is applied to the respective power window motor. The motor then drives the window up as long as you hold the switch up. The motor is grounded through the open contacts of the down relay. When you move the switch to DOWN, a signal is sent to the control unit. The control unit grounds the coil of the "down" relay, the contacts of the relay close, and voltage is applied to the motor. The motor then drives the window down as long as you hold the switch. The motor is grounded through the open contacts of the "up" relay.
When a passenger's power window is being controlled by the switch in the driver's door, the control unit in the switch sends a multiplexed signal to the control units in the other power window switches. The signal tells the appropriate control unit to energize either the "up" or "down" relay depending on the function requested. Once the relay is energized, power is supplied to the respective power window motor (see above paragraph) and the motor drives the window up or down. Since the signal is multiplexed, more than one passenger's window can be controlled by the driver's switch simultaneously.