With the engine off, and PTO CLUTCH connector disconnected, turn the key to the run position and measure the voltage going to the clutch. If you have at least 12V then your clutch is out of adjustment (some can be adjusted) or it is bad and will need to be replaced. If there is no voltage, then you are going to have to do some electrical troubleshooting to find out if the PTO switch is bad or one of the safety switches.
