Hi. I recently replaced my fuel tank and sender. 62 K-20, with a 235. Problem s that the gauge never reads full, even when the tank is full. Only goes to about 3/4 max. Also, the gauge is jumpy when the level in the tank goes down. The gauge checks out ok, it reads full when you disconnect the wire from the sender, empty when you ground it. Possibly a bad sender or, the resistance range is off? Any ideas? Appreciate your help.
