I would clean up the connections and test again for continuity. Off=open=no tone / On=closed=tone so you can rule out the switch being the problem.
All (I think) the switch does is close the loop.
You might try taking the wires off the switch, turn on key and touch them together and see if the PTO gets energized.
All (I think) the switch does is close the loop.
You might try taking the wires off the switch, turn on key and touch them together and see if the PTO gets energized.