So you pull up on the PTO knob and nothing. Nada. Not even a sound. Here are some tips that may help you get that riding lawn mower PTO working once again.
With you in the seat, turn the key one click to the on position. Now pull the PTO knob up and you should here a fairly obvious clicking sound. This is the magnet engaging the clutch plates and pulling them together. If you don’t hear anything, check for 12 volts DC at the connector that is about a foot away from the clutch. It could be beneath the chassis or above it near the starter. If you have 12 volts DC there, check the connector at the clutch to be sure it hasn’t come loose. If it hasn’t, more than likely your PTO clutch is bad and needs replaced or adjusted. Most of the time the clutch is bad so it normally is replaced.
If you do not have 12 volts DC, check your fuses to see if they are good. You should have 12 volts DC going across them as well. If they are good, you could have a bad PTO or Seat switch.
Check those switches for power and continuity to rule out why you do not have power going to the PTO clutch on your riding lawn mower.