Thanks Red, that is what I did. I just find it odd that the gauges reads a bit. When it was at quater I added fuel via a jerry can to see if the needle would move and it didn't. Maybe I will ad more fuel and see if it will budge off the 1/4 mark.
AL
OK, so lets assume the ground is sufficient. Short the sender wire to ground and turn the switch on. If needle races to 'F' in a smooth motion. Turn the switch off and replace the sender.
If the needle should do anything different , the gauge or its power supply is at fault.