Defroster, Rear

The heated rear window defroster system consists of a switch assembly mounted on the instrument panel, a relay/timer mounted in the instrument panel, a series of grid lines baked on the inside surface of the rear window and system wiring. The grid lines consist of two layers. The first layer is brown in color as viewed from the exterior, and the second layer is silver in color as viewed from the interior.

The switch assembly has a lever, spring-loaded to center position, to turn the system on or off. A timer-controlled relay turns the system off automatically after approximately 10 minutes of operation. If more than 10 minutes are required, the system can be reactivated for another 10 minutes by pushing the lever momentarily to the ON position. This operation can be repeated as required.

When the lever is pushed to the ON position, the normally open contacts in the relay/timer are electrically closed, thus providing power from battery to the heated rear window grids, the indicator and also triggering the timing circuit. This contact will remain closed until the timer turns it off, the lever is pushed momentarily to the OFF position, or the ignition switch is turned to the OFF position.

Power for the rear window grids and the indicator is supplied directly from the battery side of the starter motor relay through a fuse link which protects the circuit.

Power for the control timer comes from the accessory terminal of the ignition switch. This power is available whenever the ignition switch is in the RUN position. This circuit is protected by a fuse, located in the fuse panel.