Fuel Gauge Woes

[cebra]

I built a new wiring harness from headlight to taillight after a small fire and wired in a 1992 Blazer fuse panel and some add-ons (tach/gauges/wiper module/radio/LS harness feed/VSS/etc). Anyways, I cannot figure out what is up with my fuel gauge. I first wired it as seen in the pic...(looking from the back) Switched 12V to the right post and sender feed to the left post. Then I realized the bottom/middle post is a ground and needed to run a ground to that. So I have these 3 wires hooked up and it went from below empty (before adding the ground) to way past full and is stuck there. It should be ~1/2 tank of gas at the moment. Any suggestions?

Side note, I am running a mid-90's S-10 sender and it worked fine before the rewire less 1/8 tank was E and an inch of the sweep went past full when it was full. I was fine with this as I just want to know when I am running low as I use 1 tank of gas every 1.5 days. Thanks.