Twilight Sentinel

The Twilight Sentinel/DRL Module is mounted to the back of the Headlight Switch. All input and output signals applied to the module must pass through the Headlight Switch.

The Twilight Sentinel systems functions are controlled by the twilight enable switch, twilight delay rheostat and the Twilight Photocell. When the twilight enable switch is in the OFF position, the Twilight Sentinel/DRL Module's twilight enable input terminal (5B) is grounded. This signals the module not to operate the twilight and delayed exit functions. When the module's twilight enable input terminal (5B) is not grounded the module will enable the twilight and delayed exit functions.

The twilight delay rheostat is connected to the Twilight Sentinel/DRL Module's twilight delay input terminal (7B). As the delay rheostat position changes the resistance across the rheostat changes. This signals the module as to how long it should keep the lights on after the ignition has been turned OFF. When the rheostat's resistance is approximately 4000 ohms the delay exit timeout is about 3 minutes. When the rheostat's resistance falls to 1 ohm the delay is no more than 1 second.

The Twilight Photocell is a variable resistor whose resistance changes as the level of ambient light around it changes. The Twilight Sentinel/DRL Module monitors the resistance of the Twilight Photocell at terminal 8B. The module interprets a photocell resistance of 90k ohms or higher as nighttime and will turn on the headlights and exterior lights. A photocell resistance of less than 72k ohms is considered daylight signalling the module to turn off the lights. If the Twilight Sentinel/DRL Module detects that the photocell circuit is open, the module will default to the nighttime mode.