1972 Chevy Van Alternator problems

Electrical problem
1972 Chevy Van V8 Two Wheel Drive Automatic

My alternator is not charging my battery and my battery is dead. I jump start with another battery to get the van running, and when I disconnect my battery, the van stops running, telling me that it is also not supplying voltage to the engine. I have checked the alternator while still in the engine at auto zone and they said the alternator is bad.

I then removed the alternator from the engine and again had it checked on Auto Zones machine. This time they told me that the alternator is good! I took the alternator to another place they put it in their machine and they also told me that the alternator is good.

The Alternator that originally came with the van was replaced with the newer model (HAN 7133) that has the voltage regulator built in it when the engine was rebuilt. They left in the old voltage regulator which caused a small drain on the battery. I took out this regulator and that problem went away.

There is +12 volts going into the back of the alternator. Also the two wires that go into the connector that goes into the side of alternator were taken out, and we are not sure which wire goes into each slot. Does anyone know how I can troubleshoot this further for I am at a loss.