Okay, you're looking in the wrong direction. If it dies while you are driving, as described, it's not a parasitic load at all. It's simply that the charging system isn't working.
You didn't do the test that I wanted you to do. What I wanted you to do was to monitor the voltage while your were driving, not before and after but while. While you are driving it should be around 14. Clearly from your description, it is not.
It could be your alternator (even though it is new), it could be the voltage regulator (if you didn't change it with the alternator), or it could be a wiring problem.
The answer to your last question is yes. The alternator can and must provide enough current to run all the loads on the car and charge the battery at the same time. While the engine is running, there should never be any current drawn from the battery.
Last edited by joegr; 11-15-2012 at 11:54 AM.