I recently installed a new sending unit for the gasoline gauge on my boat. Before installing the new unit, the needle on the gauge would move in a negative direction slightly when the switch was engaged. The new sending unit is not the same make or model as the original. With the new unit, the needle swings sharply to the full position even though the tank is only about 1/3 full. Will I need to replace the actual gauge with one that is made for this particular sending unit or could something else be wrong? The old sending unit was definitely bad because the metal contact on the wing was damaged and was not making contact with the rheostat.