Gas gauge keeps moving to empty even after filling tank

SOURCE: gas gauge

The float that moves the gas hand is possibly stuck in the tank. If there's isn't an access hole in the rear of the vehicle you'll have to drop the tank. Unless it becomes free on it's own. Hope this is helpful. Please rate. Thanks

SOURCE: Fuel gauge registers empty after fill up

It sounds to me like you have a short in your wiring harness at you fuel tank. there is a plug on top of your fuel tank that controls you fuel pump and your sending unit that tells you how much fuel is in the tank. This plug can be a real p.i.a to get to on some vehicles, you may have to take the vehicle to a shop to fix it, if you are not mechanically inclined.

SOURCE: gas gauge reading empty even when tank is full

Usually if the gas gage does not work yes it is true it may be the sensor if it is electronicly controlled. the sncor will more than likley be in the tank. here is how to remove your gas tank.

1. Before servicing the vehicle, refer to the precautions section.
   
2. Relieve fuel system pressure.
   
3. Drain the fuel tank.
   
4. Remove or disconnect the following:
   
   • Negative battery cable
     
   • Fuel filler and vent hoses
     
   • Fuel tank skid plate
     
   • Fuel tank wiring connectors
     
   • Fuel supply and return lines
     
   • Fuel tank
     
   • Fuel pump assembly
     Fuel pump assembly mounting
     

1. Install or connect the following:
   
   • Fuel pump assembly
     
   • Fuel tank. Tighten the bolts to 27 ft. lbs. (36 Nm).
     
   • Fuel supply and return lines
     
   • Fuel tank wiring connectors
     
   • Fuel tank skid plate
     
   • Fuel filler and vent hoses
     
   • Negative battery cable
     
2. Start the engine and check for leaks.
   

SOURCE: Filled up gas tank and gauge still shows empty. I

ethanol fuel effects the fuel sending unit ,even just 10% ethanol.New sending units from gm adress this.

SOURCE: 2005 Nissan Xterra gas gauge reads empty when full of gas.

Sending unit died. can be expencive to replace since most sending units are integral with the fuel pump now. lots of labor too. Better to use the trip odometer till you can afford a day without your car and a $600.00 +labor repair bill.