Heated Glass Control Module: Description and Operation

The timing circuit for the Rear Window Defogger is contained internally within the cluster. When the ignition is ON, the first actuation of the Rear Window Defogger switch initiates a 10 (ten) minute time cycle. After 10 (ten) minutes of the same ignition cycle has elapsed, the cluster will turn the defogger OFF by opening the ground to the Rear Window Defogger Relay. If the defogger switch is actuated a second time during the same ignition cycle, the cluster will turn the defogger OFF after 5 (five) minutes. While the defogger is on, depressing the switch a second time will turn the defogger off. If the ignition is turned OFF while the defogger is operating, the defogger will remain OFF when the ignition is cycled.