Fuel gauge problem on my 84 C10

[Joe69C10]

Ok, I'm stuck. I've done some testing and here is where I am. (Single tank)

Gauge stays at 1/4 tank all the time. key on or off.

Tested sending unit with ohm meter and it seems to be functioning properly. I filled the tank and got 92 ohms. drove it all day and this morning and I am down to 60 ohms.

I cut the wire about mid chassis and when I did this it goes to full. When I ground the sender wire running to the gauge to goes to empty. This would mean the gauge is working right??

I even bought a new sending unit, and wired it up as a test dummy & moved the float. all the way down it actually moved the gauge from 1/4 to empty. But when moving the float up, the gauge wont go past 1/4.

Any ideas or suggestions?? I'm stumped.

Its weird, like the gauge worked when I ground and remove the sender wire. It moves the full sweep, but when I connect the sender with ohms that should move it to full it wont go past 1/4!