Circuit Operation - Interior Lights Dimming

When the park lights are on, battery positive voltage (B+) via CKT 32 (YEL) is applied to the interior dimming switch in the headlamp switch. The interior dimming switch controls the amount of current applied to the incandescent lights. As the amount of current increases, the lamps become brighter As the amount of current decreases, the lamps become dimmer.

The radio, heater and A/C control assembly, instrument cluster, and head-up display each has a vacuum fluorescent (VF) display. When each module receives an input that the ignition switch has been turned to the RUN position, each module activates its VF display at full intensity. When the park lights are on, each module receives the dimming level from an input on CKT 8 (GRY). All modules with VF displays then adjust the dimming level of their VF display to match the level of the incandescent lamps.