With the ignition switch in the RUN position, voltage is applied to the rear defogger switch. When the rear defogger control switch is pressed, voltage is applied to the solid state timing circuit. The solid state timing circuit provides voltage to the following components:

The rear window becomes warm. The warmth removes condensation from the surface of the window.

The contact in the timing circuit stays closed until one of the following actions occurs:

The first time that the rear defogger control switch is pressed, the timing circuit allows the rear defogger to operate for approximately 10 minutes. After the initial cycle, each time that the control switch is pressed, the timing circuit operates for approximately 5 minutes. The timing circuit resets to 10 minutes when the ignition switch is turned to the OFF position.