fuel gauge not working
 

I dont know where to post this cause this site turned into a cluster mess but,,Ok so my car was a 97 v6 an now a mostly 99 ls1 formula. All wire harnesses came from same car but the stereo wires were cut (the ones on the pass side going back to the amp). Now i cant get the fuel gauge to work, put diff pcm, sending unit and dash in an nothing changed. When i turn car on it goes down untill the fuel level in the tank is about 1/4 full then it will show full on the gauge. I am lost an there is nothing more then ticks me off then a broken fuel gauge,, please help with your ideas of what this could be. I cant find a wire diagram anywhere on interweb either... As far as i can see all wires from sending unit are hooked up an all grounds are good

I'm researching a similar problem and from what i have read its usually the fuel sending unit or the gauge cluster. try doing a search, there are a few threads about this problem.

Changed them all already still nothing