Changed circuit board, the duel fuel gauge still 1/4 full when full

[pali7]

I changed out my 1982 printed circuit board for my dual tanks. Before the change, it registered empty for empty and 1/4 for full. The gauge did not start moving from 1/4 full until is was actually a 1/4 tank. Exactly the same on both tanks. No difference after changing the printed circuit board. I cleaned all contacts. Could be the gauge or the wiring from the sending units to the printed circuit board? Any experience/knowledge on this problem? Thanks

 

[mtnmankev]

I think it's time to test the sending units in the tanks and make sure the connections (especially grounds) are clean and tight.
With the key ON, unplug a sender wire at the tank and ground it, the gauge should go to full.
Repeat for the other tank.
The sending units control voltage to ground after passing through the gauge in the dash.
If you get the same result you get now when the sending wire is grounded, suspect a faulty gauge.