RAM 2500 Van V8-318 5.2L VIN T Magnum CNG SFI (1997)
Daytime Running Lamp Control Unit: Description and Operation
CIRCUIT OPERATION - CANADA
On Canadian vehicles, the low-beam headlamps operate when the ignition switch is in the RUN position and the headlamp switch is OFF.
When the ignition switch is in the START or RUN position, circuit A1 from fuse 16 in the Power Distribution Center (PDC) connects to circuit
A21. Circuit A21 powers circuit F18 through fuse 19 in the fuse block. Circuit F18 feeds the DRL module.
Circuit L20 from the headlamp switch connects to DRL module. Circuit L20 is HOT at all times.
The DRL module receives the vehicle speed sensor input from circuit G7. Circuit G34 from the DRL module provides power for the high beam
indicator lamp in the instrument cluster.
Circuit L4 powers the low beams of the headlamps. When the headlamp switch is OFF, the DRL module powers the low beams on circuit L4.
When the headlamps are ON, 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 stops supplying power to the low beams on circuit L4.
Circuit Z1 provides ground for the DRL module.