Mower Blades start up randomly and then doesn't shut off

[Dave's Hoops]

I have a John Deere x320 and my mower blades start running randomly and then they don't stop unless I shut the mower off. This happened a week ago and now when I start the mower the blades start up in a few seconds even without me pulling the pto switch. I got a new PTO pull switch but that didn't stop the problem. Lost as what to do.

 

[ILENGINE]

The bottom bearing in the pto clutch may be seizing up causing it to turn the blades.

 

[bertsmobile1]

OR you might have a random short.
Unplug the clutch and drive around a bit , particularly over rough ground
If the blades do not spin then as Ilengine mentioned , new clutch time .