* Power Supply: The fuel gauge receives power from the ignition system, which is activated when the key is in the "run" position. This allows the gauge to receive a signal from the fuel level sensor.
* Fuel Level Sensor: This sensor, located in the fuel tank, measures the fuel level and transmits a signal to the gauge.
However, there are some exceptions:
* Older Vehicles: Some older cars might not have a fuel gauge that works with the engine off. The gauge might only activate once the engine is running.
* Electrical Issues: Faulty wiring, a bad fuel level sensor, or a problem with the gauge itself can prevent it from working, even with the key in the "run" position.
Bottom line: It's usually expected for the fuel gauge to work with the engine off and the key in the "run" position, but it's not a guarantee. If you're unsure, consult your car's owner's manual or a mechanic.
