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Fuel Gauge Inoperative

  1. Turn ignition to ON position. Observe other gauges and indicators. If other gauges operate normally, cluster is receiving battery voltage and grounds are good. If other gauges do not operate normally, go to step 4). If testing fuel gauge with resistors, go to step 2). If testing fuel gauge with substitute fuel tank sending unit, go to step 3).
  2. Disconnect wiring harness connector from fuel tank sending unit. Connect 145-ohm resistor (or Rotunda Gauge System Tester 021-00055 set to 145 ohms) between harness connector Yellow/White wire terminal and ground. Turn ignition on. Fuel gauge should read at or above FULL mark. Connect 22-ohm resistor (or Rotunda Gauge System Tester 021-00055 set to 22 ohms) between harness connector Yellow/White wire terminal and ground. Turn ignition on. Fuel gauge should read at or below EMPTY mark. If gauge does not respond as indicated, replace gauge. If gauge functions as indicated, replace sending unit.
  3. Disconnect wiring connector from sender and connect it to substitute sending unit. Ensure sending unit is grounded. Move sending unit float to FULL position (away from filter). Turn ignition on. Gauge should read at or above FULL mark. Turn ignition off. Move sending unit float to EMPTY position (toward fuel filter). Wait about 30 seconds then turn ignition on. Fuel gauge should read at or below EMPTY mark. If gauge does not respond as indicated, replace gauge. If gauge functions as indicated, replace sending unit.
  4. Ensure battery voltage is present at warning-indicator fuse in fuse block. Partially remove instrument cluster to ensure 2 cluster harness connections are secure. See INSTRUMENT CLUSTER R & I  under REMOVAL & INSTALLATION. Using DVOM, ensure battery voltage is present at cluster connector by backprobing battery terminal (Red/Yellow wire). Using DVOM, check continuity of cluster ground circuit. Repair as necessary.
  5. Ensure ignition is in OFF position. Disconnect fuel gauge sending unit harness connector. Use Rotunda Gauge System Tester 021-00055, or use resistors as in step 2). If using tester, install tester in cluster side of harness connector Yellow/White wire and set to 22 ohms. If using resistors, install 22-ohm resistor in cluster side of harness connector Yellow/White wire and connect other end of resistor to ground.
  6. Turn ignition to RUN position, wait 60 seconds then read fuel gauge. Fuel gauge should read EMPTY. If gauge does not read EMPTY, turn ignition off. Remove instrument cluster and inspect flexible printed circuit for opens in fuel gauge circuit. If circuit is okay, remove anti-slosh module from rear of cluster.
  7. Remove tester (or 22-ohm resistor) from harness connector. Using jumper wire, connect tester (or 22-ohm resistor) directly to fuel gauge "S" terminal on rear of cluster. Install instrument cluster to its 2 harness connectors. Turn ignition to RUN position. If fuel gauge now reads EMPTY, replace anti-slosh module. If fuel gauge does not read EMPTY, replace fuel gauge.
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