Circuit Operation - Interior Lights Dimming

When the park lights are on, battery positive voltage (B+) via CKT 32 (YEL) is applied to the panel dimmer module. The interior dimming switch in the headlamp switch is a variable resistor which applies the dimming input via CKT 44 (DK GRN) to the panel dimmer module. The panel dimmer module supplies a variable voltage via CKT 8 (GRY) to the incandescent lights in response to the interior dimming input received. The panel dimmer module receives ground from G105 via CKT 251 (BLK/WHT).

The radio, heater and A/C control assembly, and instrument cluster 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, the radio and instrument cluster receives the dimming level from an input on CKT 8 (GRY). The radio then relays this information to the heater and A/C programmer. All modules with VF displays then adjust the dimming level of their VF display to match the level of the incandescent lamps.