charging system blues

Find the two smaller wires on the back of your alternator that has power to it with the key on.
There better be one with power to it or there's your problem.:D
Leave the big one alone.(It has battery voltage all the time normally)
You will need to pull both of the smaller ones off and find the one with power when the key is on.

Now that you have identified the one with power plug that one back on and ground the other connection spade to the body of the alternator with the motor running.
If it charges now and your battery voltage goes up it tells you the alternator is ok and the problem is likely the regulator. (Which needs a good ground by the way)

You should hear the alternator load increase when you ground the one terminal to the case.
It'll spark a little when you ground it and that is ok.
What you are doing is verifying power to the alternator field and manually doing what the regulator does by completing the circuit for the field so it can produce voltage.