Ford Mustang: electrical problem, starter solenoid, mustang coupe

Question
The vehicle I am having problems with is a 1988 aerostar.The problem specifically is a short to ground in the main power harness that runs from the alternator to the battery.  I must be missing something here. I am a trained tech but cannot wrap my head around this one. Heres the problem.As long as the main power wire connector(black with orange stripe pair) from the alternator to the starter solenoid battery junction is disconnected the vehicle is fine.As soon as you plug the harness into the alternator the fusible link smokes and burns up. This would seem like a fairly simple problem.Short to ground inside the alternator right? New alternator same problem. I have pulled this harness completly apart and there is no problem with it.I have tried two new alternators.No avail.Whatever I am missing is so obvious but I just can't see it. To describe it a different way.Holding a new alternator in my hand unbolted from the engine but connected to the vehicles wiring.As I try to mount the alternator there is a huge spark and current draw through the body of the alternator from theblack wire with an orange stripe. The original alternator bench tested faulty and I've had two new rebuilds out of the box both bench testing good.Again I see this problem quite simply as an internally shorted altenator yet that is not the problem.

Answer
The second I saw the subject I groaned.  Wiring and electrical is the absolute last thing that I am an expert on when it comes to vehicles.  I electricuted myself just trying to install a new set of headlights on my 68 mustang coupe the other day.  I wish I could help you, but I have no idea why what you did wouldnt have worked.

Sorry!
Taylor