no power from kx161 at switch

[jgetz22]

no problems when i shut off but 2 hrs later went to start and i get nothing at the switch, checked battery voltage and it shows 12+volts until i turn the switch then shows 0.2v at the battery and at the fuse panel. No lights come on at the instrument panel at all. Checked cables and noticed the positive post cable end was split from corrosion so i cleaned and replaced with a new end but still get same result, checked the 50a and 60a slow blow fuses the manual says to check and even replaced them to be sure and still nothing. I then took the cpu from underneath the seat and tried it on another kubota we have same year same model and it started that kubota fine but i did notice afterwards when i hooked back up the 2nd kubotas original cpu, it wont go full throttle only idles. i never tried the 2nd kubotas cpu on the original kubota since it did start after plugging in the original kubotas cpu. Maybe i should remove battery cables (reset) the 2nd kubota battery after plugging in the cpu? Any help would be appreciated