depending on where the damage was, you either smashed wires, dislodged connection on top of tank, or ruined sender inside tank. you will need to check where damage under vehicle was done & check wiring. from there assuming wires to & from sender o.k. under car, tank will have to be dropped to access connecter on top or remove sender & pump assbl'y. to replace. suggest you do the pump while you're there if it hasn't been done recently, as it would suck to repair sender, then 2 week's later, the pump quit's!