Gas gauge always full (1968 Barracuda)

Note photo of back side of my dash. Printed circuit tracer w + id 12v in, the tracer w 6 is the 5 5-6V output to the 3 gages. The ivr i made attaches to red to the 12v stud, the yellow to the 6v output stud, and a black goes to cluster housing ground. The larger red and black jumper wires are from the volt gage i converted the ammeter to. Theres plastic grommets insulating them from touching the housing that is ground, they jumper to the 12v feed, and case ground. I have since removed the black wire from the volt gage, and have its leg ground to the housing where it bolts in. I reused the ammeter needle and face so it appears stock except when you shut the car off it goes to full discharge. There is a potentiometer or pot on the volt gage so you can fine tune the needle where you want it to sit at 13.5v after modding it to fit. I also used dimmable LED 5630 peel and stick strip lighting to line the gage housing for better illumination. Phone acting up. Will send pix later.