Headlamp Washer System Operation

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Battery voltage is supplied to the headlamp washer relay switched input. The windshield washer pump control circuit is spliced to the headlamp washer relay. When the windshield washer switch is pressed, battery voltage is supplied on washer switch signal circuit to the headlamp washer relay which energizes the relay. This allows battery voltage from the headlamp washer relay switched input to relay switched output to supply voltage circuit of the headlamp washer pump. The windshield washer fluid level switch also provides a signal circuit to the headlamp washer relay and does not allow the relay to be energized when the fluid level is insufficient for pump operation. The dash integration module controls the ground of the headlamp washer relay and the headlamps must be on for the relay to receive ground and operate. On the early production vehicles, the headlamp washers activate with each windshield washer cycle on the domestic vehicles and after every 3 windshield washer cycles on the exports. For later production vehicles, all headlamp washer systems activate after every 5 windshield washer cycles.