Alternator polarity?

You have the "rebuilder's surprise." Somebody oughta sue the **** out of those people. Here is what you have. A 50-50 chance. The isolated field units whether squareback or round, have TWO field terminals and they are supposed to BOTH be isolated from the case/ ground. Those are 70/later and one goes to switched power, the other to the VR

So if you get "lucky" and hook the ungrounded one to the blue (power) it will just overcharge........like a *****..........but if you are unlucky and get the blue hooked to the grounded one, you can smoke some wiring.