Rear (Liftgate) Wiper Circuit Operation

CIRCUIT OPERATION
The rear wiper system in this vehicle uses three switches located in the HVAC control. The operator selects the desired mode of operation from one of the three switches. The HVAC control converts the operators request to a varying analog signal that is sent to the Body Control Module (BCM) on the V26 circuit.

Each of the switches used in this system use a Light Emitting Diode (LED) to indicate to the operator what mode the system is in. Power for the LED's is supplied from the HVAC control. Ground for the LED's is supplied on circuit Z2 and terminates at the instrument panel ground.

This system is also vehicle speed sensitive.

Power for the rear wiper motor is supplied from the BCM on circuit V13. The V7 circuit is connected from the BCM to the motor and used for measuring the dwell of the motor.

Ground for the wiper motor is supplied on circuit Z1 and terminates at the liftgate ground.

When the rear washer motor is activated, the BCM provides a ground path for the V20 circuit. This circuit connects from the pump motor to the BCM.

Power for the washer motor is supplied on circuit F1. This circuit is protected by a 6 Amp Positive Temperature Coefficient (PTC) in location 9 of the junction block.