Bought a new sending unit mu dodge f the outlet was 180 degrees off. Not a problem for me. It worked, sort of --not enough that I fully trusted it, so I'd write down the miles (Painful to see the awful MPG i was getting, but..). Now the gauge doesn't move at all, except to move up to "empty" when the key is turned on. I decided to fix it and here is what I have done so far, Removed lead from sending unit to gauge and grounded it -gauge moved quickly towards full Removed sending unit from tank--float still attached and not "fuel logged" . Hooked test light to sending unit and batt. and grounded SU. Moved float up and down and test light brightness reacted. Back in truck, hooked SU backup to wire to gauge, held edge of SU to tank to ground it, and moved float --no reaction from gauge. SO what am I doing incorrectly, what to do next , or??? HOWEVER, just bough a new take-off 33 gal. round tank with all brackets, etc to hang on the side of the frame that fits perfectly. My Dodge originally had an aux. tank as the 3 position valve is still in the floor in front of the seat.