Heated Glass Element: Description and Operation

When the Ignition Switch is turned to "RUN," voltage is applied through the IGN Fuse to the Heater and A/C Control Assembly and the Rear WDO Defogger Relay. When the Rear WDO Defog Switch is pressed, voltage is momentarily applied to the Rear WDO Defogger Relay through CKT 292. When voltage is applied to the Rear WDO Defogger Relay, the Rear WDO Defogger Relay will close the internal contacts. The internal contacts remain closed until the defog cycle is complete or Rear WDO Switch is pressed a second time.

When the internal contacts of the Rear WDO Defogger Relay are closed, voltage is applied to the Rear WDO Defogger Grid and Indicator.

The Rear WDO Defogger Relay contains an internal timer to control the time the internal contacts are closed. When the Ignition Switch is turned to "RUN" and the Rear WDO Defogger Switch pressed for the first time, the defog cycle lasts 10 minutes and further operation will result in 5 minutes defog cycles. The defog cycle is reset to 10 minutes when the Ignition Switch is turned to "OFF" and back to "RUN."