If you interupted the switch circuit for the alternator (it runs through the amp light), this can cause the alt to not charge. A dynamic test would have shown the alternator having no output.
Does your amp light work? It should prove-out when you turn the key to accessory. If it never comes on, the bulb is bad or the circuit has been interupted and your alternator doesnt know that it needs to start charging.
Good luck.