Rear Defogger: Description and Operation

The rear window defogger and door mirror defogger system are controlled by the time control unit.
With the ignition switch in the ON or START position, power is supplied
^ to the rear window defogger relay terminal (1) and
^ to time control unit terminal (5)
^ through 1O A fuse [No. (10), located in the fuse block (J/B)].
Ground is supplied to terminal (12) of the rear window defogger switch through body grounds (M3) and (M90).

When the rear window defogger switch is ON, ground is supplied
^ through terminal (11) of the rear window defogger switch
^ to time control unit terminal (3).
Terminal (15) of the time control unit then supplies ground to the rear window defogger relay terminal (2).
With power and ground supplied, the rear window defogger relay is energized to operate rear window defogger and door mirror defogger for about 15 minutes.