Hi Joe, In 1950, the wiring scheme followed exactly the crude little drawing I made in the re-direct thread. And the gauge would go to E when the ignition was off. If you are stuck at FULL when the battery is not connected, then I would say something has gone wrong with your gauge. I have seen one of these get stuck on FULL, however. I never really understood why it happened, however once it was un-stuck it worked fine. I thought the needle must have become stuck against the gauge plate, but honestly by the time I got it disassembled, it had gotten freed so I never really knew for certain. Let's take a look at your gauge...image below. As you see there is only 1 moving part. That is the pivoted needle/permanent magnetic hourglass shaped piece of steel. With your ohmmeter, check the resistance between the two connections (wires to ignition and to sender not connected). You should see around 23~25 ohms if I recall correctly. Let's start there.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
