hey guys im new on here and ned some wiring help

hey just bought a 79 k 20 mud truck its got 44 boggers and a pain in the butt 327 ive been replacing everything from brakeboster to stering to the interior i have ran into a problem the other day i went to start it and it starts off a kill switch 1 for direct power and a toggel for the ignition anaways it was runing like a top then it died i tryed to chatch it when the engine died maybe fired on 1 cylinder and i hit the switch it clicked like the battery was dieind or the cylinoid was going so i killed everything tryed to start the truck again and nothing absoutly nothing so i pulled the starter took it to the auto parts store and they got it to work they said the the main power terminal was loose very loose on the cylinoied anaways i cant get it to work i have power going to everything so if ya'll could help i would appreicheit it this is driving me nutz thanks guys