. When we returned the the toy alternator it  failed every test the machine gave it, and WAS NOT BAD when we installed, we had it tested right out of the box. And it was installed with a new regulator from the start.

This is exactly what I went through too.  I bet if you pulled the sub harness that goes from the alt up to the main harness and peel all the tape off you'll find a problem in there somewhere.  My problem was I bought my truck from a house electrician, he had done a couple of splices in that harness and when I tested with an ohm meter a couple of the wires were very inconsistent.  I redid the splices and it all checked out good, no problems since.