SER. MANUAL UPDATE SEC.8A I/P ILLUMINATION OPERATION

Subject: INSTRUMENT PANEL ILLUMINATION FEATURE OPERATION

Model and Year: 1991 LUMINA

TO: ALL CHEVROLET DEALERS

The 1991 Lumina is equipped with an instrument panel illumination feature which is a function of the light switch. This illumination feature operates as follows:

With any door open or with the light switch in the "DOME" or "INT" position, terminal D of the light switch receives a ground signal from the door jamb switch through the WHT (1 56) wires (see page 8A-l 14-1) or internally through the light switch. When the last door is closed and the light switch is not in the "DOME" or "INT" position, or when the light switch is moved from the "DOME" or "INT" position with all doors closed, ground is removed from terminal D of the light switch. The light switch then supplies voltage for about 30 seconds through the GRY (8) wires to illuminate the instrument cluster, radio, heater and A/C control assembly, console PRNDL, ashtray, and the front door lock and window switches (see pages 8A-l 17-0) and 8A-l 17-1.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.