PTO engagement blows fuse

I have a craftsman pro series 24hp 46" riding mower (model 247.204420). When I took it out of winter storage, I replaced the battery, and mistakingly connected the battery incorrectly (positive to the negative post, and ground to the positive post). After failing to be able to start my tractor, I recognized my mistake, and correctly connected the battery. The tractor starts fine, but as soon as I engage the PTO switch, the fuse blows. I realize I have probably damaged something by reversing polarity when I connected the battery the wrong way. My question is, what do I trouble shoot, and replace first? Thank you.

Check electrical connections at PTO switch, electric clutch, & seat switch looking for burn marks. Also check jumper wire harness at PTO clutch as well as everything behind dash. Sears Parts Direct has your parts listed.

There is next to nothing that is polarity sensative apart from the ignition module and regulator so apease your guilty conscience.
Most likley during the winter small furry things took up residence in your mower and have chewed through a wire.

We did have a similar problem a while back that turned out to be ants nesting in the PTO switch.
You can start by disconnecting the clutch at the plug which should be some where around the starter motor.
If the fuse does not blow when you turn the blade on then the problem is in the clutch or the wiring from the plug to the clutch.
otherwise carry on as previously advised

I replaced the PTO switch, and the tractor works great now. Thanks for the help.