Hi and thanks for using 2CarPros.com. I have to be honest, it sounds like even though the alternator is new, it is bad. If I understand correctly, with the engine running, there is no increase at the battery as far as voltage. Just in case, here are general directions for checking it. (you may have already done this.)
After the test, check to make sure all connections and wiring to the alternator are clean and tight. If everything looks good, I recommend removing the alternator and having it bench tested. Most parts stores will do it for free. Here are the directions for removal and replacement.
Be sure the battery connections are not reversed, because this will damage the rectifier.
Do not use high-voltage testers such as a megger, because they will damage the rectifier.
Remember that battery voltage is always applied to the alternator B terminal.
Do not ground the L terminal while the engine is running.
Do not start the engine while the connector is disconnected from the L and S terminals.
Remove in the order shown in the figure.
Inspect all parts and repair or replace as necessary.
Install in the reverse order of removal.
I hope this helps.
Wednesday, May 9th, 2018 AT 8:55 PM