Pulled the wire and got 86 ohms. So I guess that means the sender is at least working. How accurately it is working remains to be seen. So next I am going to check if there continuity along the wire from the terminal to the gauge. If that is OK how do I check the gauge without doing it harm?

‘72 Charger, 5.9 Magnum, Tremec 5 spd., Pro-Touring
‘14 Big Horn, Quad Cab, 4x4, 1500