The fuel gauge wasn't working at all in my 70. I grounded the sender lead wire at the tank and a friend observed movement in the gauge so I went ahead and replaced the sender / fuel pick up. The gauge does now work, most of the time. However is sticks. Smacking the dash above the cluster will cause the needle to move. I guess my question is, has anyone ever seen this behavior? Would this be the physical gauge? The resistor? A bad ground? All the gauge lights work so I am doubtful of bad ground. I am guessing gauge or resistor. Feedback appreciated.
Being as only ground is the sender, that's not the problem. If reading hangs with switch off, it's mechanical. Otherwise problem is likely either the gauge voltage regulator, resistor or related wiring.
