Its probably the fuel level sensor that went bad. 96-98 have the fuel level sensor separate from the fuel pump assembly. Its possible if u bought it the previous owner changed the fuel pump and damaged the fuel sensor. Also could be unplugged but id check sensor first
1996 Mustang GT, 17x9 front and 17x10.5 cobra r replica rims, 255/40/17 front 285/40/17 rear at the moment,
o/r x-pipe flow master 40 series dump downs, cai/ram intake, 75mm c&l throttle body and plenum, pi heads and intake swap, msd wires, stock gears, untuned at the moment, no dyno numbers for now.