[cooperino]

I would start by testing the pto. I have a power probe that I am able to provide voltage to test things like this. To test i would disconnect power wire from main harness, apply power to just the pto wire with it out of the circuit. I would first try it with engine off. While applying power see if the clutch spins freely or if you are turning the engine. If the engine turns, the pto is engaged. if not then you have a pto issue. With the engine off you should here the pto click when power is applied. Divide and conquer! If the pto tests good the next thing i would do is start testing for continuity between switch and pto. You will need a correct wiring diagram to test beyond that.

Good luck