Voltage is applied through fuse 4 to the rear defogger switch in the heater-A/C control when the ignition switch is turned to the RUN position.
A solid state timer controls the battery voltage from fuse 4 through a relay. Voltage is momentarily applied to the timer. The voltage activates the relay that controls the rear window defogger grid when the rear defogger switch is pressed.
The relay remains closed by the timer until one of the following actions occurs:
| • | The defog cycle is complete. |
| • | The rear defogger switch is pressed a second time. |
The defog cycle lasts for 10 minutes when the following actions start the cycle:
| • | The ignition switch is turned to the RUN position. |
| • | The rear defogger switch is pressed for the first time. |
Further operation will occur in 5 minute defog cycles.
The defog cycle resets to 10 minutes when the ignition switch is turned to the OFF position and back to the RUN position.
The defogger ON indicator is an LED that illuminates when the rear defogger is ON. This LED will be step dimmed by the LED indicator control when the park lamps are turned ON.
