To troubleshoot:
1. Check the Instrument Cluster Fuses: Your owner's manual will show the fuse box diagrams. Look for fuses related to the instrument panel, gauges, or power to the instrument cluster. These are the most likely candidates if a fuse is the problem.
2. Check the Fuel Level Sensor: This sensor is located in the fuel tank. A faulty sensor can prevent the gauge from working correctly. This usually requires a mechanic to diagnose and replace.
3. Inspect Wiring: Look for any damaged or loose wires leading to the instrument cluster or fuel level sensor. This can be difficult and may require professional help.
In short: Don't focus on finding a "gas gauge light fuse." Focus on the fuses related to the instrument panel and power to the gauges as a starting point. If replacing those fuses doesn't resolve the issue, professional diagnosis is recommended.