Electrical Tracking down my always full fuel gauge issue....89 Notch

[fakesvo]

Like it says I got a 89 Notch that has a fuel gauge reading way past full despite the tank being close to empty. As far as I know the gauge hasnt worked even before I owned it. The car is a swap car now housing a 2.3T if it matters.

Im going to start with checking out the Anti Slosh unit in the back bypassing it temporarily to see if it helps. If that doesnt help id like to check the wiring from the tank connector to the dash but im a bit confused on verifying it.
If I wanted to check it for any breaks between the tank and dash can I simply just do an ohm test on each wire from the tank sending unit to the dash cluster? I was told that if the gauge goes to full its possibly a broken wire grounding itself out somewhere in the car, if I wanted to check that could I just touch each side of the fuel sending unit connector to a ground anywhere on the car? Or if I disconnected the tank sending unit wires and put a ohm tester on it, it would read around what 150-180 ohms if it was truly full??

Last resort is dropping the tank and looking at the float and whatnot.

 

[General karthief]

Does the gauge move when the key is turned off?

 

[fakesvo]

Does the gauge move when the key is turned off?

Yes I noticed that the gauge goes to like half way with the key off.

I pulled the cluster out and took a look at the Anti Slosh unit and visually it seems fine. I saw a way to bypass it which i might try for the hell of it.

 

[fakesvo]

Can somebody confirm is this diagram is right and im understanding it correctly. According to thing the fuel tank sender connects to Pin 10 (YELLOW/WHITE) on the dash cluster connector B.


I just want to ohm out this single wire back to the tank to confirm its fine. If that isnt broken can I simply just run a new ground wire from the sender to the chassis if thats the issue??

Thanks everyone!