Wiper/Washer System Description
WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Battery positive voltage is applied from the WIPER/WS fuse to the switch side of the WIPER relay. Battery positive voltage is also applied from the body control module (BCM) to the WIPER and WIPER HIGH relay coil circuits when commanded by the wiper switch.
Ground is applied continuously from G200 to windshield wiper motor and to the coil sides of the WIPER and WIPER HI relays. The BCM also provides a ground to the windshield wiper/washer switch.