Fuel Gauge Problem

[kgc1966]

The fuel gauge on my 96 is jacked. I’ve changed gauges and when I plugged the connector in and tested it it pegged past full. I get that means a fuel sensing problem in the tank. Crazy thing is, when I plug in the connector for the tach, the gauge drops back below empty. Anyone know what could cause this? Circuit board issue maybe?

 

[miesk5]

Yo KGC,
Welcome!
Testing in a 96; "...I had the fuel gauge pegs past E blues. Both trucks had gas logged floats..." by wood4

■ fuel gauge Ground G200 in lower side of passenger side plastic kick panel

Section 13-01: Instrument Cluster, Conventional

1996 F-150, F-250, F-350, Bronco, F-Super Duty Motorhome Chassis Workshop Manual​

DIAGNOSIS AND TESTING
Pinpoint Tests
PINPOINT TEST A: FUEL LEVEL READS INACCURATELY
A1 VERIFY POWER AT LOAD SIDE OF FUSE PANEL

• Key to RUN.
• Using Rotunda 88 Digital Multimeter 105-00053 or equivalent, verify system voltage at the load side of fuse.

Is the voltage greater than 10 volts?

Yes	No
GO to A3.	GO to A2.

A2 VERIFY POWER AT FEED SIDE OF FUSE PANEL

• Key to RUN.
• Using Rotunda 88 Digital Multimeter 105-00053 or equivalent, verify system voltage at the feed side of the fuse.

Is the voltage greater than 10 volts?

Yes	No
REPLACE the fuse.	REPAIR the wiring to the fuse panel.

A3 VERIFY POWER AT INSTRUMENT CLUSTER

• Have cluster connector(s) remain intact.
• Partially remove the instrument cluster from the instrument panel.
• Key to RUN.
• Using Rotunda 88 Digital Multimeter 105-00053 or equivalent, measure the voltage on the ignition wire at the instrument cluster connector to ground.

Is the voltage greater than 10 volts?

Yes	No
GO to A4.	REPAIR the ignition wire.

A4 VERIFY GROUND CIRCUITRY AT CLUSTER

• CAUTION: Before checking the continuity of any circuit, make sure there is no voltage present in the circuit prior to switching the test equipment to the resistance function, to avoid damage to equipment. Refer to the test equipment user's manual for additional information.
• Using Rotunda 88 Digital Multimeter 105-00053 or equivalent, check the continuity of the ground wire at the instrument cluster connector to ground.

Is the resistance less than 1 ohm?

Yes	No
GO to A5.	REPAIR the wire to ground.

A5 CHECK FUEL GAUGE (EMPTY)

• Key off.
• Disconnect the fuel gauge sending unit.
• Connect one lead of the Rotunda Instrument Gauge System Tester 014-R1063 or equivalent to the fuel level sensor input wire at the fuel tank sending unit connector and the other lead to ground.
• Set the tester to 22 ohms.
• Key to RUN.
• Read the fuel gauge.

Does the fuel gauge read E (empty)?

Yes	No
GO to A9.	GO to A6.

A6 RECHECK FUEL GAUGE (EMPTY)

• Key off.
• Key to RUN.
• Tap on the instrument panel.
• Read the fuel gauge.

Does the fuel gauge read E (empty)?

Yes	No
F-Series, Bronco, F-Super Duty: REPLACE instrument cluster . F-Super Duty Motorhome: GO to A7.	GO to A9.

A7 CHECK PRINTED CIRCUIT BOARD

• Key off.
• Disconnect the instrument cluster.
• Measure the resistance of the circuit between the SIG terminal of the fuel gauge and connector Pins C1-05 and C2-06.

Is the resistance less than 1 ohm?

Yes	No
GO to A8.	REPLACE instrument cluster.

A8 CHECK FUEL GAUGE SENDING UNIT WIRE

• Key off.
• Disconnect the instrument cluster and the fuel tank sending unit.
• Measure the resistance of the Y/W wire (F-Series front) or Y/LB wire (F-Series and Bronco rear) between the instrument cluster and the fuel level sensor.

Is the resistance less than 5 ohms?

Yes	No
GO to A9.	SERVICE the DB/Y wire (F-Series front) or Y/LB (F-Series and Bronco rear) wire between the instrument cluster and the fuel level sensor.

A9 CHECK CHASSIS GROUND

• Key off.
• Leave instrument cluster and fuel level sensor disconnected.
• Measure the resistance of wire to chassis ground.

Is the resistance less than 5 ohms?

Yes	No
SERVICE short to chassis ground.	GO to A10.

A10 CHECK FUEL TANK SENDING UNIT GROUND

• Key off.
• Measure the resistance of the BK wire at the fuel level sensor connector to ground at battery.

Is the resistance less than 1 ohm?

Yes	No
GO to A11.	SERVICE the BK wire from the fuel level sensor to ground.

◇
ASAP, find out if speed control recall work, if equipped was completed. If you still have concerns about Recalls, please contact the Ford Customer Relationship Center:
US: 800-392-3673 | CA: 800-565-3673
Note: 3673 spells "FORD" on phone keys
For the hearing- or speech-impaired: Please contact the Telecommunication Relay Service by dialing 71
... have VIN ready.
"Summary: ON CERTAIN PICKUP TRUCKS, PASSENGER VEHICLES, SPORT UTILITY VEHICLES, AND MOTOR HOMES CHASSIS, THE SPEED CONTROL DEACTIVATION SWITCH MAY, UNDER CERTAIN CONDITIONS, LEAK INTERNALLY AND THEN OVERHEAT, SMOKE, OR BURN. THIS COULD RESULT IN AN UNDERHOOD FIRE."
To confirm current status, use this guide by jowens1126 @ 93 & 94-96 Cruise Control Recalls Repair
Note that the 93 recall is different than the 94-96 recall.

Here's the 1996 Bronco/F-Series Workshop Manual partial

96 Bronco Owner's Guide, Maintenance Schedules & Parts and Accessories by Ford @ Owner Manuals | fleet.ford.com

96 Bronco Dealer Brochure @ 1996 Ford Bronco Technical Info pictures, videos, and sounds | SuperMotors.net ... scroll down

96 Bronco Quick Tips Brochure Excerpts & some Eddie Bauer options @ 1983 Ford Bronco 96 EB Bronco Brochures pictures, videos, and sounds | SuperMotors.net
Al

 

[johnnyreb]

I never knew the float (plastic-foam like ones gas log) Thanks Mike. Glad I have the brass one and will stick with them.