Dazed and Confused
Join Date: May 2012
Location: Upstate New York
Re: 1962 f350 gas gauge
If I insult your level of knowledge, I apologize in advance. A fuel gauge and it's respective float has to match. Not all floats provide the same resistance at full and at empty, but they have one thing in common, an empty tank will result in a higher resistance and a full tank will be a lower resistance. As much as I can gather, if your gauge is OEM, it's expecting a sending unit that provides about 15 ohms full and 80 empty. That is the rating for an in-cab sending unit, but since they use the same gauge regardless of tank location, I would surmise a mid ship or rear tank should be the same. The gauge, itself works by a heater strip that when the resistance is high, has less voltage going through it and cools causing the needle to move towards empty. A fuller tank will provide a higher voltage to pass through the heater, causing it to heat up and move the gauge towards full. When testing, verify that the float meets these resistances without power attached, then test the actuation of the float with power attached, making sure that it is grounded. If your wiring is good, you may have cooked the heater on the gauge.
Ever notice that there's so many high performance parts available for GM products?
Did you ever think that maybe they NEED them?