fuse problem

hello all, my son started his king quad 300 drove it up on my trailor, shut if off and now i get no lights or anything?? i checked the fuse up front by battery and it was blown. 20amp i replaced it and as soon as i plugged it in it blew again. i tried another it did the same thing. I am thinking for no apparent reason , i have a short. i dont understand why this would just happen. any ideas gang? i could use some help with this one.

my dad has an older 250 king quad and he has problems in the wireing down the handlebar stem. thats probably where i would start looking. his doesn't blow fuses but it wont do anything until you wiggle the handlebars and then it will start