You fill up your gas tank, you turn on the ignition, but the fuel gauge needle doesn't move. This sure sign of a problem can have numerous causes. Troubleshoot your car's fuel gauge before seeking the help of a mechanic.
Ensure that all of the wire connections are clean, secure and corrosion-free.
Check your fuel gauge fuse if the gauge's indicator stays on empty when your turn on the ignition. If the fuse is good, join the sending unit connector to ground. Replace the sending unit if the gauge indictor moves to the full line.
Ground the terminal located on the back of the fuel gauge with a jumper wire if the indicator doesn't move. If it does move, consider replacing the wire between the fuel gauge and the sending unit. A poor ground is frequently responsible for fuel gauge problems.
Release the wire that connects to the fuel tank's sending unit. Confirm that there's no worn insulation that would permit wire contact to the body or frame. A fuel gauge reading of full generally indicates a problem with the tank unit, not the wiring.
Consult a mechanic if you can't pinpoint the source of your fuel gauge's problem.