I recently got a Husqvarna ZTH5225A and it didn't run , one problem was it didn't turn over or even click with a hot battery , it turned into a two fold problem , I was getting no voltage to the ignition or starter solinoid , I repaced the relay on the left side the mower as I found water had gotten into it and corrided the points in there and after changing it would power up with key in accessory position but blow the fuse when turned to start , I really scrathed my head alot on this one tracing wires looking for a short , I unplugged the ignition switch and jumped two wires to the plug , one to power up the accessory and one to jump the starter solinoid , it started and ran , changed the switch for $17 and it is working fine --------------- from what I learned troubleshooting my problem , your problem could be in the saftey system , if the park brake is not set , the blade engagement switch engaged or the seat sensor not making contact it won't get voltage to the ignition switch --------- good luck and Happy Holidays