Parking brake off ? Seat safety switch problem ? What lights do you have on when you turn the key ? You imply that it cranks OK, Is that right ?
Fuel shut off should pull in (click) before you turn the key the rest of the way to crank it up. Pull in circuit is powered by a wire directly from the starter, so all neutral start conditions must be satisfied in order to energize the solenoid pull in windings. There is also a 25 amp fuse in this circuit.
My guess is either the seat switch, fuse, or TDC (Time delay control module). Could maybe be the PTO sensor as well. It may think the PTO is still on. This can happen if the PTO sensor switch gets moved out of position. Check this from underneath.