Under the drivers seat you will see the sender. Should have three wires on it plus a fuel line. Do the check that wantaquad suggested but if nothing then I suggest that you remove the sender. You can do this by undoing the fuel line first and un hooking the wires (take a photo so you remember which ways the wires go back!) and then there is a metal ring with three tabs that twists anti clockwise I think. The sender is held in by this twist ring pushing against the lip of the tank. You can then lift the sender out, its just a long tube for sucking up the fuel with another piece of metal with a float on it that rises and falls with the fuel level and the arm of the float drives a rheostat that indicates the fuel level. Get a new sender, they are cheap. Fit that and if still nothing then you have a wiring issue which is a pain. Good luck!