Rear Defogger: Description and Operation

CAUTION: Grid lines can be damaged or scraped off with sharp instruments. Care should be taken in cleaning glass or removing foreign materials, decals or stickers. Normal glass cleaning solvents or hot water used with rags or toweling is recommended.

The rear window defogger system, also known as electrical backlight (EBL), consists of two vertical bus bars (1) linked by a series of grid lines (2) fired onto the inside surface of the rear window (3).

The EBL system is turned ON or OFF by a control switch located on the A/C-heater control at the center of the instrument panel and by a rear window defogger relay timing circuit integral to the front control module (FCM).

Circuit protection is provided by a fuse located in the junction block (JB) and a fuse located in the power distribution center (PDC).




The electric backlight (EBL) system is controlled by a momentary switch (2) located in the A/C-heater control (1) on the instrument panel. When the defogger switch for the EBL system is pressed to the On position, current is directed to the rear defogger grid lines and the heated power mirrors (if equipped). The heated grid lines heat the glass to help clear the rear window and side mirror surfaces of fog or frost.

A yellow indicator (3) in the defogger switch will illuminate to indicate when the EBL system is turned on. The front control module (FCM) contains the EBL system control circuitry.

NOTE: The EBL system turns off automatically after approximately 15 minutes of initial operation. Each following activation cycle of the EBL system will last approximately 10 minutes.

The EBL system will be automatically turned off after a programmed time interval of about 15 minutes. After the initial time interval has expired, if the defogger switch is turned on again during the same ignition cycle, the defogger system will automatically turn off after about 10 minutes.

The EBL system will automatically shut off if the ignition switch is turned to the Off position, or it can be turned off manually by depressing the defogger switch a second time.