Grand Cherokee 2WD L6-4.0L VIN S (1997)
Daytime Running Lamp Control Unit: Description and Operation
CIRCUIT OPERATION
Canadian vehicles are equipped with a Daytime Running Lamps (DRL) module. If the headlamp switch is in the OFF position, the DRL module
operates the high beams of the headlamps at 50 percent intensity when the ignition is in the RUN position and the park brake is off. Circuit A6
from fuse 13 in Power Distribution Center (PDC) powers the DRL module. Circuit G9 provides the park brake signal to the DRL module.
In the RUN position, the ignition switch connects circuit A1 from fuse 8 in the PDC to circuit A22. Circuit A22 supplies power to circuit F83
through fuse 6 in the junction block. Circuit F83 splices to the DRL module.
Circuit L3 powers the high beams of the left and right headlamps. When the headlamp switch is OFF, the DRL module powers the high beams on
circuit L3. When the headlamps are ON, the dimmer switch in the multi-function switch powers the low beams on circuit L4.
Circuit L3 feeds the high beams of the headlamps. When the operator flashes the headlamps with the stalk of the multi-function switch, the DRL
module senses voltage on circuit L3. When it senses voltage on circuit L3, the DRL module signals the Body Control Module (BCM) on circuit
G34. In response, the BCM turns on the high beam indicator lamp in the instrument cluster.
