When you go to turn the key on your riding mower it should start but, sometimes that's not always the case. Their are a number of things that could be wrong. First, it could be your key switch. You can have that tested at your local mower repair shop. Second, is your solenoid wire. you might want to test that to see if its getting power with a test light. Third, could be your solenoid itself. If there is nothing but clicking, this could mean you have a dead battery or your solenoid is bad.