So I did the gauge cluster swap and everything went smoothly. Execept for ONE thing. My gas gauge .
When the key is in the ignition the gas gauge moves all the way past F, then the "almost empty" light comes on. I took the dash apart, re-seated all of the plugs/connections and it happened again. I took the cluster out and looked at the back to see if any of the screws in the back were loose and not making a connection and EVERYTHING looked fine.
What do you think the issue is? Its not my fuel sending unit because it worked fine with a previous cluster I had. I'm just stumped on this one

 

I feel your pain brother. Cluster issues suck.

The only thing I can think of is a short 'somewhere'.

Is the cluster brand-new? Used? You may have everything on correctly but the new gauge is faulty? Is there a way to test the fuel gauge seperately? A OhM resistance check maybe? If it goes to infinity, there is a break. If it reads ~0 the circuit is complete.

 

The cluster is used from a pick n pull
I actually installed some "glow gauges" and I doubt theyre causing the problem but I was running the same cluster before the glow overlays and the fuel gauge was working fine.
The gauge has 3 connections Ignition, Ground, and "FU" which is probably the sending unit signal. I can test it seperately just by taking the 3 connection screws out which allows me to pull the entire gauge out of the cluster. Im just wondering wouldn't it be a complete circut already because the light is on and the needle moves past F? Am I maybe getting only ignition and ground which would cause full power to go to the gauge and make it max out? Thanks for your help man! I hate driving around worrying about running out of gas haha