Dimming Potentiometer
The scan tool displays the voltage value indicating the position of the dome lamp switch (thumbwheel). The scan tool displays 0 (zero) volts when the headlamp switch is in the AUTO position and the daytime running lamps (DRL) are ON. The scan tool displays 10.5 volts when either the park lamps or the headlamps are turned ON and the dome lamp switch is in the FULL BRIGHT position.