FixVault
Home › Ford › 1993 › Probe Base, Automatic › Repair and Diagnosis › Electrical › Gauges › Instrument Panel - Analog › Testing › Fuel Gauge Circuit Test

Fuel Gauge Circuit Test

NOTE: Some testing procedures will require Gauge System Tester (Rotunda 021-00055).
  1. Ensure METER fuse is okay. Turn ignition off. Unplug connector from fuel pump. Connect Gauge Tester (021-00055) between Red and Black wires on harness connector. Turn ignition on. Set tester to resistance specified in FUEL TANK SENDING UNIT RESISTANCE table. If fuel gauge indicates as specified, go to next step. If fuel gauge does not indicate as specified, go to step 3).
    FUEL TANK SENDING UNIT RESISTANCE

    Fuel Gauge Resistance (Ohms)
    Full 7
    3/4 19
    1/2 35
    1/4 65
    Empty 105
    Low Fuel Warning Light 90
  2. Turn ignition off. Disconnect tester. Measure resistance between Yellow wire on harness connector and ground. If resistance is not less than 5 ohms, go to next step. If resistance is less than 5 ohms, replace fuel tank sending unit.
  3. Turn ignition off. Unplug 14-pin connector from instrument cluster. Turn ignition on. Measure voltage at Black/Yellow wire on 14-pin harness connector. If voltage is greater than 10 volts, go to next step. If voltage is not greater than 10 volts, repair Black/Yellow wire between connector and fuse panel.
  4. Turn ignition off. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Remove fuel indicator module from rear of instrument cluster. Remove low fuel warning bulb. Measure resistance between pin 1F of instrument cluster and pin "F" of fuel indicator module. Measure resistance between pin 1F of instrument cluster and low fuel warning light connector. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, replace instrument cluster printed circuit board.
  5. Measure resistance between 14-pin connector pin 1I (Black wire) and ground. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair Black wire to ground.
  6. Measure resistance between instrument cluster pin 1I and fuel indicator module connector pin "C". Measure resistance between instrument cluster pin 1I and fuel gauge "-" terminal. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, replace instrument cluster printed circuit board.
  7. Measure resistance between Yellow wire on 14-pin harness connector and Red wire on fuel pump harness connector. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, repair Yellow or Red wire between instrument cluster and fuel pump.
  8. Unplug connector from fuel pump. Measure resistance between Yellow wire at instrument cluster harness connector and ground. If resistance is greater than 10,000 ohms, go to next step. If resistance is not greater than 10,000 ohms, repair short in Yellow wire.
  9. Measure resistance between instrument cluster pin 1H and fuel indicator module connector pin "A ". If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, replace instrument cluster printed circuit board. Measure resistance between instrument cluster pin 1H and fuel gauge pin "F". If resistance is less than 5 ohms, go to step 12). If resistance is not less than 5 ohms, replace instrument cluster printed circuit board.
  10. Measure resistance between fuel indicator module connector pin "B" and fuel gauge "+" terminal. If resistance is less than 5 ohms, go to next step. If resistance is not less than 5 ohms, replace instrument cluster printed circuit board.
  11. Reinstall fuel indicator module. Attach 14-pin instrument cluster connector. Leave 16-pin connector free. Remove "+" screw from fuel gauge. Turn ignition on. Measure voltage at "+" fuel gauge terminal on circuit board. If voltage is greater than 10 volts, replace fuel gauge. If voltage is not greater than 10 volts, replace fuel indicator module.
  12. Turn ignition off. Remove instrument cluster. Remove low fuel warning bulb. Measure resistance between bulb terminals. If resistance is approximately 12.6 ohms, go to next step. If resistance is not approximately 12.6 ohms, replace bulb.
  13. Unplug fuel indicator module. Measure resistance between fuel indicator module pin "D" and low fuel indicator bulb connector. If resistance is less than 5 ohms, replace fuel indicator module. If resistance is not less than 5 ohms, replace instrument cluster printed circuit board.
About FixVault