Thanks for the replys, I am going to take my gauge to work and play with it. I have access to power supplies and potentiometers so I can simulate the sender and I can control the current flow. I let you all know if I found out anything.

52 Chevy 3100 5 Window, LS Swap, 4spd Auto, Vintage Air AC / Heat, CPP Power Front Disc Brake Conversion with bearing upgrade, Power Steering Conversion, LED Tail Lights