2nd gen fuel gauge issue

Hi everyone. The fuel gauge on my 2nd gen kind of works. It moves between 3/4 and way over full tank, depending on how much is in it.
I had a local shop drop the tank and put a new float in it and still have the same issue.
We think it could be the gauge itself...
What fits?
Anything else I need to look at?

Donivan has a couple of posts on trouble shooting both the gauge & the sending unit installed. Search on them; I would rely heavily what he has provided.


If no joy pull the sending unit & check:
a) if you have continuity across the full range of arm movement
b) It goes from zero (down or empty position) to 90 ohms (up or full position).

Let me know what that produces, maybe the linkages for the potentiometers are out of whack
Gary

Does it seem to work when Empty, 1/4, 1/2 and 3/4,,,,,,,,or just go crazy when between 3/4 and Full?,,,,,,did they just put a float in the tank or a sending unit in it,,,,,,,,,you got a 0-90 ohm system,,,,,,,,however,,,,,,you got a useless 16 gallon 1st Gen gas tank,,,,,,,and we use a 0-30 ohm sender in them,,,,,,,,easy for someone to mix things up if they dont understand the difference,,,,,run a test on the wire that goes to the sender on the top of the gas tank,,,,,unplug it or disconnect it from the connector behind the left rear tail light,,,,,,the test is if you disconnect the wire, the gas gauge should go to Full when you turn the key on,,,,,,ground that wire and the gauge should read Empty,,,,,,,see what you get,,,,,,,,,,,