When the park lamps are on, battery positive voltage (B+) is applied to the park lamp input in the panel dimming module. The dimming switch on the headlamp switch varies in resistance as the dimming switch is operated. The panel dimming module receives a variable input voltage based on the resistance of the dimming control. The panel dimming module supplies a variable voltage to the incandescent lamps. The voltage is proportional to the voltage input from the dimming switch. The lamps become brighter as the voltage level increases. The lamps become dimmer as the voltage level decreases.

The following components have a VF display:

When a module receives an ignition in RUN input, the module activates the VF display at full intensity. When the park lamps are on and the vehicle senses nighttime conditions, the lamp control module (LCM) supplies a dim enable signal to the components. When the module receives the dim enable input, the module dims the VF display to the current dimming level. The radio and instrument cluster receive the dimming level input via the variable dimming output circuit from the panel dimming module. The HUD has a separate dimming control on the HUD switch in the overhead console. The HUD receives the dimming level input from the instrument panel cluster dim enable circuit. The heater and A/C programmer receive the enable and dimming level inputs from the radio through the VF dimming circuit.