Rear Window Defogger System Components
The optional rear window
defogger system consists of the following components:
| • | A rear window defogger switch |
| • | A rear window defogger relay/timer |
| • | 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 right
side and the ground terminal (1) is soldered to the bus bar on the
left side.
Rear Window Defogger Operation
When the ignition switch is in the ON position, ignition voltage is
applied to the defogger relay, through the DEF fuse.
When the rear defogger switch is depressed, a ground signal
is provided to the defogger relay through the switch to G200. This activates
the timer circuit and relay, which provides battery voltage through the
closed contacts of the relay to the indicator in the switch and to the
rear defogger. The rear defogger is a resistive element grounded at G401
and begins to heat as soon as voltage is applied. The indicator is grounded
at G200 and illuminates as soon as voltage is applied.
The defogger relay incorporates an integral timing circuit. The timer
circuit will terminate the rear defogger operation after 15 minutes. 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 |
