Rear Window Defogger System Components
The rear window defogger system consists of the following components:
| • | A rear window defogger switch |
| • | A rear window defogger relay |
| • | A rear window defogger grid |
The rear window defogger grid is a resistive element composed of ceramic silver compound adhered to 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
Battery positive voltage is supplied through the DEF fuse, in the IP fuse block, to the rear window defogger relay switch. With the ignition in the ON position, ignition voltage is supplied through the GAUGE fuse, in the IP fuse block, to the rear window defogger relay coil, and to the rear window defogger switch. When you depress the rear window defogger switch, the switch illuminates the rear window defogger indicator and grounds the control circuit of the rear window defogger relay. This energizes the rear window defogger relay and allows battery positive voltage from the relay switch feed circuit through the closed switch contacts and out the relay switched output to the rear window defogger grid. Ground for the rear window defogger grid is provided by G300.
The rear defogger switch incorporates an integral indicator lamp. The indicator illuminates when the rear defogger switch is depressed. The rear window defogger stays on until it is manually turned off. If the ignition is turned off while the rear window defogger is on, the defogger turns back on automatically when the ignition is in the ON/RUN position again.
