To further diagnose the problem we need a wiring diagram and for that we need the full numbers from the ID tag.
To double check. pull the blower housing off and remove the kill wire (s) to the coil.
I the engine starts & engages the blades fine then you have a fault in that wire.
IT should be open circuit with key on, some one in the seat & pto switch on
It should go closed to ground if the person gets off the seat with the PTO on or if the person gets off the seat PTO OFF but parking brake not on.