Like CARNAC said, do both, I had alt one go out on me so I bought a rebuild kit, and the day I went to go rebuild it, ALT2 went out. I was due to go to a show that evening, so I just thought I would rebuild alt 1 as the truck will run on just ALT1 in a pinch.
Low and behold, the idiots I was doing business with, sent me the wrong parts for the kit. Hence, no taking the truck to the show. And no ability to transport my wares to the show to sell. I was livid.
They did ultimately send me the correct parts. I did them both the same day in about an hour.
I was an idiot for waiting until the last minute, and they were idiots for making multiple mistakes, and not offing to make anything right.
I’ll be rebuilding a spare as soon as I get hold of a rebuild able core.
From the factory, both alts are isolated grounds. But you only need it on the passengers (ALT2) side. If you look, there is a wire that grounds ALT1 negative post to the engine. Therefore, the isolated ground on that side is negated. But it makes them interchangeable.
