Battery Discharge Protection Relay: Description and Operation

CIRCUIT OPERATION
The headlamp delay uses a relay located in the junction block. Power for the relay is supplied on circuit A3. This circuit powers the coil and contact sides of the relay and is protected by a 40 Amp fuse located in the Power Distribution Center (PDC) cavity 15.

The relay is activated by the operator turning OFF the ignition with the headlamps ON. The Body Control Module (BCM) controls the ground for the coil side of the relay and the amount of time the headlamps stay ON. Circuit G50 connects the coil side of the relay to the BCM.

When the relay is energized, the contacts in the relay CLOSE connecting circuits A3 and L4. Circuit L4 is used to power the fuses used for low-beam headlamp operation.