Incandescent Dimming
WARNING: This page is about a different car, the 2003 Pontiac Montana, 2003 Oldsmobile Silhouette, and 2003 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
The incandescent lamps become illuminated when the parklamps are on. The brightness of all the incandescent lamps, except the radio incandescent lamps, is determined by a variable voltage signal produced by the dimmer switch and sent through the instrument panel lamp supply voltage 1 circuit. The incandescent lamps are located in various components (see schematics).