VACUUM FLUORESCENCE DISPLAYS FLICKERS OR GOES BLANK

SUBJECT: VACUUM FLUORESCENCE DISPLAYS FLICKER OR GO BLANK (REPAIR OPEN OR SHORT IN CIRCUIT)

VEHICLES AFFECTED: 1985-91 'C'

Some 1985-1991 DeVilles and Fleetwoods may experience a condition of vacuum fluorescence displays flickering or going blank and/or the Electronic Climate Control (ECC) blower going off. This may be the result of a loss of power or ground to the Body Control Module (BCM) or an internal problem with the Digital Instrument Cluster (DIC), ECC, Fuel Data Panel (FDP), or ECC power module/blower.

Within the BCM there is a regulator which provides 16 volts for the Vacuum Fluorescence (VF) displays of the DIC, FDP, and ECC. This regulator also provides the variable 16 volt input the ECC power module for blower speed control.

To diagnose and repair these conditions use the following trouble tree.

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.