I havea 1990 chevy 2500 withthe 5.7 andIfilled her up yesterday and the gauge moved about a cm from 1/4 tank. I disconnected the sending unit ground and the gauge didnt move so I hit it with a wire brush and put it back on. Im sorta lost any ideas?

 

try taking the leads that come off the meter, and with a AA battery very quickly,momentarily complete the circuit. This should tell you if the meter still somewhat fuctional. remember very quickly and do not leave it on long as it will "PEG" the meter.

 

FUEL GAUGE COIL IS TWISTED...

 

Try this, unplug the sender wires that go into fuel tank, turn your key on, the gauge should move to a 3 oclock position (open circuit). If you were to get a jumper wire and put on the violet colored wire and attach it to ground the gauge should go to empty. If the gauge does not do either of these, the dash gauge is bad. If it does ok, the tank sender is bad.