Interior Lamps Dimming

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. 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
HVAC control head assembly
Radio
The instrument panel cluster (IPC)
Other interior controls and switches

When the ignition switch is turned to the ON position, the radio's vacuum fluorescent (VF) displays turn on at maximum brightness. When the park lamps are on, 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. Battery positive voltage is supplied through the PARK LPS 30A fuse in the engine wiring harness junction block, to the normally open park lamp relay switch contacts. The panel dimmer switch potentiometer receives both its voltage and ground from the headlamp switch and is an input to the BCM. When the driver selects a dimming setting by moving, the IP dimming switch potentiometer, all incandescent back lighting lamps are provided with a specific voltage. The incandescent back lighting lamps are then grounded at G203 and G200. 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.

The driver may select parade mode by manually turning on the park lamps during daylight conditions. The front park lamp circuit supplies voltage to the instrument panel cluster, radio and HVAC assembly for a park lamp on input, and the displays will become full bright.