Gauges incorrect...voltage limiter upgrade

took the sending unit out and wired it up so I could sit in the drivers seat, manipulate the float arm. it reads half full will the float arm about 3/4 of the way up. Once I move it down to about 1/4 to it lowest point the gauge starts reading empty. No dead spots when I ohmed it out, maybe ill pull the cluster and see if I'm missing any grounds and replace the ivr...