GM Service Manual Online
For 1990-2009 cars only

Voltage is available to the panel dimmer switch assembly when the headlamp switch is in the PARK or the HEAD position. The voltage goes through the ILLUM 10 Amp Fuse (Fuse 14) to the following components:

    • The instrument cluster lamps
    • The radio
    • The HVAC control module
    • The rear window wiper/washer switch
    • The overhead console and compass
    • The auxiliary heater switch
    • The auxiliary air condition switch illumination lamps.

The grounds for the lamps are through various paths.

The headlamp and panel dimmer switch illumination lamp receives voltage from the gauges fuse when the ignition is in the RUN or START position. Ground G110 supplies the ground for the headlamp and panel dimmer switch illumination lamp. The headlamp and panel dimmer switch illumination lamp illuminates at the full intensity when the parklamps are in the OFF position. When the parklamps are in the ON position, voltage is supplied to the illumination lamp from the PK LPS fuse. The lamp can then be dimmed with the panel dimmer switch.