gas gage barley moves

[dstaple]

gas gage not working, can someone help me , when i ground the sending unit wire at the tank the gage goes to F. where do I go from here?

 

[RustyRatRod]

The float is probably compromised.

 

[Professor Fate]

Or the tank isn't properly grounded.
At a minimum, make sure the factory ground strap is present. It is a small metal "jumper" that connects to the tank hose nipple and the fuel line- it bridges the rubber fuel line that connects the two.

There's also a pretty good lip around the tank that you could screw a strap to and attach to a body ground in a convenient place.

 

[cudamark]

Ground, float, or the sender itself. Test the ground first as it's the easiest. Add an extra ground and retest. Still bad, pull the sending unit and see of the float is flooded (After you lower the fuel level below the sender hole of course!). If so, replace it. If not, the sender is probably bad. Test with an ohmmeter. I like using an old analog needle type ohmmeter for this test. It acts more like what the gauge would. Depending on your year, some aftermarket senders are pathetic at best. Sometimes it's best to have your sender rebuilt. There again, your year plays a part here.