I replaced the sending unit in my 87 T . I can now see when the tank is empty but I went and filled it with 10 gallons of gas and it and its only right above quarter tank. Can it be my gauge? I'm pretty frustrated.
What did you replace it with, new or used? I got a new sender and ended up having to bend the arm a little - it was hitting the tub inside the tank. That was frustrating also, I know the feeling.
Just for fun, disconnect the wire plug to the sender and attach it to the old sender that you can hold in your hand. Turn the key on and raise the float arm on the old sender. Have a partner tell you if the gauge is going up. I need to replace my sender too. Darn gauge always reads low, like yours. You can also clean the contacts on the sender. http://home.comcast.net/~84gngary/sendingunit2.html