My cub cadet wont start when turning switch it makes aclicking sound that comes from on top of pullie over blade?

That is probably your solenoid. It is what tells the battery to send voltage to the starter so it will crank the engine over. Most of the time it is just a low battery that makes it make that sound. There isn't enough voltage to keep the solenoid engaged. Although, it could be a bad solenoid. If jumping it doesn't start it then it is more than likely the solenoid. If jumping does start it then you need a battery.