Interior Lamps Dimming: Notes

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

• The Door Switches and the Window Switches
• The HVAC Control Head Assembly
• The Radio
• The Traction/Suspension Control Switch
• The PRNDL
• The Fog Lamp\Rear Compartment Lid Release Switch (Domestic)
• The Front and Rear Fog Lamp Switch (Export)

When the ignition switch is turned to the ON position, the vacuum fluorescent (VF) displays, for radio and HVAC control assembly, and the incandescent lamps 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 VF displays dim in order to match the indicated dimming level. The PK\LP fuse 6 in the instrument panel electrical center supplies battery positive voltage to both the ALC PRK LP relay switch and coil contacts. The ALC PRL LP relay coil is controlled by the BCM. When the headlamp switch is placed in the PARK position, the BCM energizes the park lamp relay coil control circuit and dims the interior lamps to the dimming level indicated by the IP dimmer switch. 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. When the IP dimmer switch is moved from MIN to MAX, all VF displays and 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, the radio, and the HVAC assembly for a park lamp on input, and the displays become full bright.