THE FUEL PUMP FLOAT HAS GONE BAD OR THE GAUGE NEEDS TO BE CHECKED
The fuel gauge sending unit would be found inside the fuel tank.
either the fuel gauge needs replacing or the fuel gauge sending unit in the fuel tank is stuck
Either the gauge is broken or the sender is broken.
The cause of the faulty fuel gauge is probably the fuel gauge sending unit located inside the fuel tank. Replacing the sending unit would require dropping the fuel tank.
One reason for a gauge not working is a broken part either in the fuel tank or between the fuel tank and the dashboard - keep looking
A gauge for measuring fuel in a tank.
Most trucks with dual tanks only have fuel sensors in one tank. I disagree with that as both of them have a float in them. It is possible there is corrosion to the float gauge on fuel pump. You can either replace fuel pump and gauge in tank or take old one out of fuel tank and clean up the crude in it.. I just did this to mine and it works now.. either way you have to drop tank or take off bed which I found was easier.
Most likely either a bad float in the fuel tank or defective gauge
check for a damaged fuel tank
id say either a bad ground to chassis on the fuel sending unit (off the top of the tank.) or a bad gauge
You would need to use alternative method of checking the fuel level, such as dipping the tank.
More often than not, a fuel gauge problem is usually a faulty fuel gauge sending unit in the fuel tank.