Fuel indicator light shows empty after filling tank up

The vehicle has a saddle tank with 2 sending units, AND WILL LIKELY NEED TO BE DIAGNOSED WITH BOTH A DIAGNOSTIC SCAN TOOL AND A QUALITY METER SUCH AS A GRAPHING DVOM. If a fuel level sensor is replaced, the instrument cluster reset procedure will need to be done or the fuel level will still be inaccurate. This tells the cluster a new sensor has been installed and it will "learn" the characteristics of the new sensor.