Rear Window Defogger System Components
The optional rear window defogger system consists of the following
components:
| • | An air inlet and rear window defogger switch assembly |
| • | A rear window defogger relay |
| • | A rear window that has a number of horizontal ceramic silver compound
grid lines |
| • | Two bus bars that are attached to the inside surface of the rear
window |
The supply voltage terminal is soldered to the bus bar on the left side
and the ground terminal is soldered to the bus bar on the right side.
Rear Window Defogger Operation
When the ignition switch is in the ON position, ignition voltage is
applied through the GAUGE fuse to the coil of the defogger relay and to the
air inlet and rear defogger switch assembly. Battery voltage is applied
to the switch portion of the defogger relay at all times through the defogger
fuse.
When the rear defogger switch is depressed, the air inlet and rear defogger
switch assembly energizes the rear defogger relay by grounding the control
circuit of the rear defogger relay. This allows battery positive voltage
to the rear defogger resistive element which heats as soon as voltage is
applied.
The air inlet and rear defogger switch assembly incorporates an integral
indicator lamp and an integral timing circuit. The indicator illuminates when
the rear defogger switch is depressed. The defogger cycle lasts approximately
10-15 minutes and then shuts off automatically. Defogger operation
may be cancelled before the cycle ends by depressing the defogger switch,
or by turning the ignition switch to the OFF position.
The rear defogger switch may be depressed for additional cycles depending
on the following conditions:
| • | Outside window temperature |
