posted 04-30-2014 01:16 PM ET (US) Dash unit replaced about a year ago. Checked with the tank sending unit(moved the float up and down)to make sure it worked and it did. Boat recently in water for several hours running everywhere and gas guage not moving lower than 3/4 tank. Pulled tank unit and moved the float up and down and it would show full but not less than 3/4/ tank. Bad dash unit or bad sending unit??