GM Service Manual Online
For 1990-2009 cars only

Headlamp Washer System Components

The headlamp washer system consists of the following components:

    • Windshield Wiper/Washer Switch
    • Instrument Panel Module (IPM)
    • Headlamp Washer Relay
    • Headlamp Washer Fluid Pump
    • Headlamp Washer Circuit Breaker, 30A

Power and Grounds

Battery positive voltage is supplied to the headlamp washer fluid pump relay through the ignition 1 voltage circuit and the accessory fuse located in the underhood fuse block with the ignition in the ON or RUN position. Battery positive voltage is also supplied at all times to the headlamp washer fluid pump relay through the battery positive voltage circuit and the HDLP WSHR module circuit breaker located in the underhood fuse block. This voltage is used to run the headlamp washer pump motor. The pump motor is grounded through the pump motor ground circuit and G 101.

Headlamp Washer System Operation

When the washer switch is pressed, the windshield wiper switch sends a voltage signal through windshield washer switch signal circuit to the wiper motor module and the instrument panel module (IPM) indicating the wash command. Every fourth time the windshield washer system is commanded ON, the IPM will initiate a headlamp wash cycle by pulling the headlamp washer relay control circuit low energizing the relay. The relay then closes its switch contacts applying battery positive voltage through the headlamp washer pump motor control circuit to the headlamp washer pump motor. The pump motor then runs spraying washer fluid on the headlamps. A headlamp wash cycle consists of a prewash, then a pause, and then a wash operation.