Fuel Guage Problems

[67-72lover]

My fuel guage does not work I have replaced the fuel sending unit and the circuit board on the back of the cluster plus both resistors (which I think there bad) for the fuel and temp guage. If i pull the sending unit wire off it pegs out pass full. If I pull the sending unit out of the tank and hook a jumper wire off the negative cable of my battery to the sending unit and hook the sending the unit wire up to the sending unit and move the float it only goes to the 1/4 mark on the guage no farther I tryed this with the old and the new sending unit same thing. Can anyone give me some imput as what to try im at a total loss with it.

Thanks
Eric