I wouldl first check the sending unit to see if they sold you a 6-volt sending unit which runs on 0-30 ohms or the 12-volt sender that runs on 30-90 ohms. You need the 6 volt one to match your dash gauge. I would bet a policemans donut that you have a 12-volt sender which explains why you have limited readings you are at the top of the 6-volt scale and the bottom of the 12-volt scale...Randy

Fifth Avenue Internet Garage