Billbo

The main key fuse (25A) burns out as soon as a replace it (even with key in the off position) and even with ignition disconnected.  Any ideas on where to start looking to determine where the short is?  Or does anyone know where I can find a wiring diagram? 

Model 37bm467d710

Serial 1d042z50007

I am trying to figure out the type of battery that I should get for my 2013 Cub Cadet Volunteer.  The old battery says it was 450 CCA, but I've been having trouble finding one with exactly that in the local stores.  My wife picked up a 575CCA (26R) from OReillys.  Will that work?  Or will I ruin something by increasing the CCA?

The attached image is of my old battery.