Headlamp: Description and Operation

HEADLIGHTS
Voltage is applied at all times to the Headlight Relay and Daytime Running Lights (DRL) Relay. The Headlight Relay is mounted in the I/P Relay Center. The DRL is mounted in the Forward Lights Electrical Center. The Headlight Switch, Remote Keyless Entry/Theft Deterrent (RKE/UTD) or Central Control Module (CCM) can activate the Headlights by grounding the coil in the Headlight Relay. When this coil is energized, the relay contacts close and current is supplied to terminal "D" of the Headlight Dimmer Switch. The CCM will activate the DRL System whenever ambient light conditions (daytime) cause the resistance of the ALS to decrease. This will in turn signal the CCM to activate the DRL Relay.

FORWARD LIGHTS
Voltage is applied at all times to the Park Lights Relay. This relay is mounted in the Forward Lights Electrical Center. The Headlight Switch, RKE/UTD or CCM can activate the Forward Lights by grounding the coil in the Park Lights Relay. When this coil is energized, the relay contacts close and current is supplied to the I/P Fuse Block and Forward Lights Electrical Center. In DRL mode, the Park Lights Relay will be deactivated.

TWILIGHT SENTINEL (T82)
Twilight Sentinel (Non-DRL vehicles) works similar except for the following:
^ Twilight Sentinel can be "shut off" at will by moving Twilight Delay Slide Switch to full "DETENT" position.
^ During daylight conditions, Headlights will be "OFF" while in the Twilight Sentinel mode.
^ Non-DRL vehicles will not have DRL wiring, DRL Relay, etc.