- Check the appropriate fuse before attempting any other diagnostics.
- Raise and support the vehicle.
- Unplug the fuel level sending unit connector from the top of the fuel tank.
Insert the leads of the Rotunda gauge tester number 021-00055 or equivalent into the fuel level sender connector and set the scale to 145 ohms.
NOTEAlthough a gauge tester is recommended for the testing of the fuel level sending unit, you can purchase resistors of the equivalent value at any electrical store and form your own tool.
Turn the ignition to the
position and verify that the fuel gauge reads
. If the gauge reads
, proceed to the next step, if it does not, repair gauge and/or wiring as necessary.
NOTEIt may take as long as 60 seconds for the gauge to move.
- Slowly turn the resistance level on the gauge tester to 22 ohms and verify that the gauge reading moves to FULL . If the gauges moves to FULL , the gauge and wiring are operating as designed, most likely the sending unit is faulty, repair as necessary. If the gauge does not read FULL , repair gauge and/or wiring as necessary.
An alternative method requiring no special testers is to remove the fuel pump from the tank. Connect the wiring to the pump and sending unit and manually operate the sending unit arm while an assistant observes the gauge.