The rear defogger system consists of a timer integral to the control head which interfaces to an external relay. The function is activated through a momentary button located on the face of the control head. An amber light emitting diode (LED) in the control head will be used as a feedback mechanism in order to indicate the status of the rear defogger system, and must be active any time the rear system is active. The rear defogger system will be reset after an ignition cycle.

The first actuation of the rear defogger system of the ignition cycle shall activate the system for approximately 10.0 minutes. Successive actuation of the rear defogger system shall activate the system for approximately 5.0 minutes.

The heated outside mirrors operate in the same manner as the rear defogger system with the same on time cycle. The heated outside mirrors has a 10 amp fuse located in the underhood bussed electrical center (UBEC) that is in series between the rear window defogger relay and the outside mirrors.