Rear Window Defogger System Components
The rear window defogger system consist of the following components:
| • | HVAC control module |
| • | A rear window that has a number of grid lines |
| • | Two bus bars that are attached to the inside surface of the rear window. |
The battery voltage terminal and ground terminal are soldier to the bus bars.
Rear Window Defogger System Operation
Battery positive voltage is supplied to the heated outside rearview mirror and rear window defogger relay switch. Ignition 3 positive voltage is supplied to the heated outside rearview mirror and rear window defogger relay coil. Ground for the heated outside rearview mirror and rear window defogger relay coil is provided by G103. When you start the engine, and depress the rear window defogger switch. The HVAC control module energizes the heated outside rearview mirror and rear window defogger relay by momentarily supplying battery positive voltage to the control circuit of the relay. This allows battery positive voltage to the rear window defogger. Ground for the rear window defogger is provided by the radio antenna amplifier.
When you start the engine and press the rear window defogger switch for the first time, the defogger cycle lasts for 20 minutes. Further operation results in 20 minute defogger cycles.
