help!!! john deere 172 hydrostatic with kawasaki fc420v

wondering if you could help, i have a kawasaki fc420v in a 1989 john deere 172 with 38" deck... was given this asa hand me down from a friend... i bought a new battery and when i put it in there is a small circuit breaker (small black box 12 volt 25 amp rated )mounted to the firewall that pops and sparks as soon as it recieves power. I have jumped all saftey switches and disconected the white wire next to dipstick which i believe controls the saftey switches as well, all i get is an occasional clicking in the motor no turning over at all... any help i would greatly appreciate

 

I think your white wire is part of the ignition system and shouldn't affect your problem, but it wouldn't hurt to leave it disconnected until you get the electrical stuff straightened out so you don't burn up any ignition components. Are you certain the battery is connected in correct polarity? Are the cable connections tight? Did your friend tell you anything about what it did before you got it?