Instruments - Fuel Gauge Reads Low Constantly

Bulletin No. T 85-91
File in Group 6C
Number 99
Corp. Ref. No. 8058007
Date July '85
SUBJECT: FUEL GAUGE READS LOW

MODELS AFFECTED: 1984 RWD DE VILLES AND FLEETWOOD BROUGHAMS 1985 RWD FLEETWOOD BROUGHAMS

Figure 1: Fuel Gauge Printed Circuit Attachment:

Some fuel gauges on 1984 De Villes and Fleetwood Broughams and 1985 Fleetwood Broughams may indicate "empty" or "very low" regardless of the actual fuel level in the tank. This condition may be due to a poor connection at the rear of the fuel gauge unit. There are three threaded studs on the back of the fuel gauge housing used to retain the flexible printed circuit and calibration resistor. Each stud has two nuts that hold the printed circuit to the housing (refer to Figure 1). If one or more of these nuts are loose, an open circuit could result causing the fuel gauge indicator needle to point low or to "E". The low fuel indicator light may not illuminate with this condition.
If any of these nuts are loose, a wave washer (P/N 25046872) should be added to each stud between the lower nut and printed circuit. This will increase the clamp load between the two nuts and improve the electrical connection.

CAUTION: The nuts should be tightened to 5 to 8 in.oz. Over-tightening the nuts could strip the stud and/or damage the calibration resistor.

If this condition still exists after the above procedure, continue with fuel gauge diagnosis as outlined in 1984 and 1985 Service Manual Sections 8A and 8C.