Hey i have a 1990 jimmy i upgraded the alternator to the 140 amp but still isnt close to enought would it be worth it to hook up a second alternator in place of the ac that i took out???? i have kx1200.1 hooked up too 2 re se15" speakers 600rms each and the sx900.4 hooked up to the 4 speakers. now im also adding a second battery to the back i have a yellow and a red top now from my understanding i would only use an isolator if im playing when im parked but other than that dont use one ?? if theres any one has any advice would be great thanks