Non functioning fuel gauge in a 1996 f 250

This is why your fuel gauge in your 1990 to 1996 f 150 and f 250 might even be f 350 and f 450 if there gas, Im not sure, But I guess diesel have the same little float. If you remove the unit, hook up the wire harness and raise the lever, watch the gauge inside, and if gauge moves up, the sending unit is OK. No need to replace the entire unit, that cost around 400 bucks, Just replace the little brass float, and go. But if your experiencing low fuel pressure out either tank that you plan to address this issue, then replace the pump, and if your having an issue of fuel pumping from rear to front tank, then you will have to replace the entire unit, It depends on your individuality. My issue here is simply the fuel gauge sitting on Empty and well I just got the truck and fixed everything else, so why not the fuel gauge as well. And look, you will have 50 out of 100 people tell you to drop the tank, and the other tell you pull the bed, But look out, I do these allot, and have been for years. I have found it so much faster, and so much easier to simply pull the bed!! Why mess with a full tank of gas and draining it and all that BS!! 6 Bolts folks, and the bed is off the frame!! You have 1 harness at the lights, 6 little 7 mm bolts at the filler necks, and 6 bolts underneath. 2 people to lift the bed and set it down, so easy. FYI, If your up north, salt will eat everything up, so while bed is off, you can full inspect all the equipment on top looking down, instead of on your back looking up!! Less in your face. But to each his own, I use to work for ford dealerships, and well, this is the way I do it. So have a look and hope this helps you. Thank you and God Bless. FYI, you can also check the sending unit off the vehicle with a DVOM Digital Volt Ohm Meter, or an Analog will do as well, set to ohms, and simply raise the lever, and if OHMS change the unit is OK, If they do not change then unit is bad. But, Pull the float, shake it listen, if gas is inside, then the float is for sure bad, do not try to repair it, REPLACE it!! There only a few bucks new, and 100's in wrecking yards, just make your choice wisely, and check it before you put a used one in, or it might be bad as well, look for cracks, there the most fail, cracks around the edges. 20 bucks for a new float from Ford.