Theory Of Operation

The Body Control Module (BCM) receives the input from the Upper Switch Bank indicating that the rear defogger is requested. The BCM relay (when all required conditions are valid, e.g. roof closed, ignition Run, ect.) provides a ground path through the rear window defogger control output circuit. The rear window defogger control output circuit connects to the Rear Window Defogger Relay, which when energized provides battery voltage to the Rear Window Defogger, which is also known as Electric Back Light. The Rear Window Defogger Relay is located in the Power Distribution Center. For additional information on the Rear Window Defogger operation. Refer to REAR WIPER AND WASHER SYSTEM .