Jeep 1997 Grand Cherokee Service Manual page 871

ZG
DESCRIPTION AND OPERATION
REAR WINDOW DEFOGGER
The Body Control Module (BCM) operates the rear
window defogger system through a relay located in
the junction block. When the operator presses the
rear window defogger switch, the switch connects cir-
cuit C80 from the BCM to ground circuit Z1. In
response, the BCM grounds the coil side of the rear
window defogger relay on circuit C14.
When the BCM grounds the rear window defogger
relay coil, the contacts close and connect circuit A900
from fuse 3 in the Power Distribution Center (PDC)
to circuit C15. Circuit C15 supplies power to the rear
window defogger grid. Circuit A900 also powers the
coil side of the relay. Circuit Z1 grounds the rear
window defogger grid.
Internal to the junction block, circuit C15 splices to
feed circuit C16 through fuse 10. Circuit C16 feeds
the Light Emitting Diode (LED) in the rear window
defogger switch.
8W - 48 REAR WINDOW DEFOGGER
8W-48 REAR WINDOW DEFOGGER
8W - 48 - 3