Alternator testing

[Dave Hudson <daveh@proaxis.com>]

I think my recently rebuilt alternator might not be charging. My battery 
voltage is just under 12 volts and the voltage doesn't change when the 
car is running. (70 B) Is there a way to check the alternator and it's 
associated wiring with a voltmeter? I'm not sure which wire is which - 
there are two connectors to the back of the alt. - one has three wires, 
the other has 2 connectors but only one wire (a fat one) going to it. 
Anyone have experience and tips?  Thanks!!   Dave H