* Faulty Fuel Level Sender: This is the most common culprit. The sender unit is located in the fuel tank and measures the fuel level. It can fail due to corrosion, damage from debris in the tank, or simply wear and tear.
* Bad Fuel Gauge: The gauge itself in the instrument cluster could have failed. This is less common than a faulty sender.
* Wiring Issues: Broken, corroded, or loose wires between the fuel level sender and the gauge can interrupt the signal. This includes connections at the sender, the instrument cluster, and any connectors along the wiring harness.
* Instrument Cluster Problems: While less likely than a sender issue, a problem with the instrument cluster's circuitry or the gauge itself can also prevent the gauge from working.
* Grounding Problem: A poor ground connection somewhere in the circuit can prevent the gauge from receiving the proper signal.
While other less likely possibilities exist, starting troubleshooting with the fuel level sender is usually the most efficient approach.
