Hot Rods technical gas gauge traditonal hot rod

can any one tell me the proper way to test a gas gauge it shows full all the time two different sender 2nd one known good thanks in advance Tom

 

Disconnect the wire to the sender directly from the guage. That should peg the guage on way or the other. Next jump a wire to ground from the post on the guage(sending unit side). It should peg to the opposite side.

If it works as it should and you know the sender is good there is likely a problem with the long wire to the sender. Good luck