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Fuel Gauge Test

  1. Ensure 10-Amp "Meter" fuse in fuse panel is okay. Ensure Black/Yellow wire from fuse panel to instrument cluster supplies 12-volts with ignition on (gauge voltage is regulated to 7 volts). If fuse blows check for short to ground in Black/Yellow wire circuit. If fuel gauge always reads "EMPTY", ground Yellow wire of instrument cluster connector. Fuel gauge should read "FULL". If gauge does not read "FULL", replace fuel gauge. If gauge did read "FULL", go to next step.
  2. Ground Yellow wire at fuel tank sending unit connector. Fuel gauge should read "FULL". If gauge does not read "FULL", repair Yellow wire between fuel gauge and fuel tank sending unit. If gauge does read "FULL", proceed to next step.
  3. Ground Black wire at fuel tank sending unit connector. Fuel gauge should read normal. If gauge does not read normal, replace fuel tank sending unit. If gauge does read normal, repair Black wire between fuel tank sending unit and ground.
  4. If fuel gauge always reads "FULL", disconnect instrument cluster connector. On Festiva models, if gauge reads "FULL", replace fuel gauge. If gauge does not read "FULL", go to next step. On Tracer models, disconnect instrument panel connector (C127), apply 12 volts to connector pin "G" (Black/Yellow) at rear of panel and ground pin "H" (Black). On all models, if gauge still reads full, there is an internal short and gauge should be replaced. If not, go to next step. See Figure .
  5. Reconnect instrument cluster connector. Disconnect fuel tank sending unit connector. If gauge reads "FULL", repair Yellow wire between fuel gauge and sending unit. If gauge does not read "FULL", replace sending unit. See Figure .
  6. If fuel gauge is not accurate, disconnect fuel tank sending unit. Connect leads of Rotunda Gauge Tester (021-00038) to Yellow wire of fuel tank sending unit connector and the other lead to ground. Turn ignition on, check that fuel gauge needle indicator displays correct resistance values. See Figure . Inspection should continue for 2 minutes. If fuel gauge readings are incorrect, replace fuel gauge. If gauge readings are correct, proceed to FUEL GAUGE SENDING UNIT test.
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