Interior Lamps Dimming

WARNING: This page is about a different car, the 2002 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

The second group includes lamps which may be dimmed. This group may use a combination of vacuum fluorescent (VF) illumination and of incandescent lamps.

Door switches and window switches
Fog lamp switch
HVAC control head assembly
Hazard switch
Power sunroof switch assembly
Radio
Rear compartment lid release switch
The instrument panel cluster (IPC)

When the ignition switch is turned to the ON position, the vacuum fluorescent (VF) displays (radio) turn on at maximum brightness. When the park lamps are on and the ambient light sensor indicates low light conditions, all incandescent back lighting turn on at the dimming level indicated by the IP dimmer switch. At the same time all vacuum fluorescent (VF) displays dim to match the indicated dimming level. The PARK LPS fuse in the underhood junction block supplies battery positive voltage to the coil side and switch side of the park LPS relay. With the headlamp switch in the PARK position, battery positive voltage is supplied to the park lamp switch ON input circuit of the body control module (BCM). The BCM then supplies ground to the control circuit of the park LPS relay. The park LPS relay is energized and current flows from the park LPS relay to the instrument panel (IP) dimmer switch and to the lamp dimmer module. The dimmer module supplies a proportional voltage to the interior lamps in response to the setting of the IP dimmer switch. All the vacuum florescent (VF) and incandescent back lighting lamps are provided a specific voltage and are then grounded. Ground is provided at G201, G202, G301, and G401. When the headlight switch is turned to the PARK or HEADLAMP position, all incandescent back lighting turn on at the dimming level indicated by the IP dimmer switch. When the IP dimmer switch is moved from MIN to MAX, all vacuum fluorescent (VF) displays, as well as all incandescent back lighting respond from Minimum intensity to maximum brightness in response to the IP dimmer switch.