Twilight Sentinel

The twilight delay switch in the headlamp switch is supplied a reference voltage from the instrument panel Integration Module (IPM) via CKT 1688 (LT BLU/BLK). It is supplied a reference ground from the IPM via CKT 61 (YEL). The switch is a potentiometer that resistance varies as the switch is moved. The IPM receives an input voltage proportional to the resistance of the potentiometer via CKT 1783 (PPL). The IPM sends a class 2 message to the Dash Integration Module (DIM) indicating the on/off status and delay length for the twilight sentinel. With the twilight sentinel in an ON position, the DIM will automatically control the headlamps on/off status depending on the nighttime/daytime status of the ambient light sensor. The DIM will use the twilight sentinel delay length to know how long to keep the headlamps and park lamps on after the ignition switch transitions from ON to OFF during nighttime conditions.