[51woodie]

Clem. I'm not familiar with a '40, but if it is the same fuel gauge system as my '46 coupe, I might be able to add some info. My fuel gauge was not reading full when the tank was full. One thing that I did while testing the gauge system, (you need the ignition on) was to disconnect the power to the coil to prevent damage to the point and/or coil. Another note, when the sender (in my case) is out of the tank, there will be some gas fumes in the area of the tank opening. If the disconnected fuel sender wire touches the tank with the ignition on, it will make a spark. I tested the circuit from the sender to the gauge by using a 2' lead with clips, so I could make the connection away from the tank opening. the gauge will read FULL when the gauge wire is connected to a ground. If you get a reading, the circuit is good, and the sender or float is likely at fault. In my case the float (aftermarket I think) was partially flooded.