Circuit Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
When operation of the rear wiper is selected, battery voltage from the rear wiper switch is applied to the rear wiper switch signal input circuit of the body control module (BCM). The BCM responds by switching the rear wiper relay control circuit to ground. This action energizes the rear wiper relay, providing power to the rear wiper motor.