Good evening I’m new with the forum all though I read a bunch of helpful talks now I have a 73 camaro gas gauge when I set the Sender float at the bottom it reads empty when I move the arm what I think is half way it goes past the full mark anybody have any idea

 

Using ohmmeter, connect to s/unit chassis and terminal from the moving arm.
As you see, float on bottom - 0 ohms.
Move arm to FULL- 90 ohms.
During movement, do it slowly and watch meter as the increase/decrease of ohms should be steady/constant, no opens or jitters.