Here is an easy procedure to test the fuel gauge alone: 1) Remove the gauge from the tractor. 2)Get a 12 volt battery and hook the power terminal of the gauge to the NEGATIVE terminal of the battery. 3) Ground the base of the gauge, or the ground terminal of the gauge, if it has one, to the POSITIVE terminal of the battery. What does the gauge read? 4) Now, don't change a thing but momentarily ground the terminal that goes to the sending unit to the positive terminal of the battery. The gauge should read just the opposite as it did in the prior test. Does it?
Conclusions: Do you have gauge part# 54427? If the test don't work here it won't work in the tractor. This test is for the gauge only. It eliminates wiring and the sending unit.