GM Service Manual Online
For 1990-2009 cars only

Rear Wiper Operation

The rear wiper is controlled by an input from the rear wiper/washer switch which is located in the center console switch bank. The rear wiper/washer switch is a three position switch, when the WIPER protion of the switch is pushed into it's detent the rear wipers are turned on, a voltage signal from the BCM is applied through the wiper washer switch to the rear wiper motor to command it ON. With the switch in the center or rest position the wipers are OFF.

Rear Washer Operation

When the WASHER portion of the switch is pressed the rear washers are turned on, the switch has a momentary contact in the washer position and will continue to spray as long as the switch is being pressed and will stop when it is released. When the wiper portion of the rear wiper/washer switch is closed, B+ is applied to the REAR/WSW relay indicating rear washer operation is requested. With B+ applied to the relay coil, the relay is energized and B+ is supplied to the washer pump.