I think I have the same alternator in my 2000 Pariot. Here's a quick field fix/bandaid.
I went to head home last month from Parker, AZ. and got about 100 yards when I realized my volt meter was showing around 12 volts. Knowing this wasn't good, I determined that my alternator was bad. Since it was Sunday, I knew I won't find a replacement. So I went to the auto parts store and bought (2) 24" battery cables and tied the chassis batteries to the coach batteries (just be careful when doing this) I turned my generator on and drove home.
side note: While on the generator, my volt meter was showing 14 volts, then about an hour into the drive, it showed 15 volts (my normal reading) So when I got home, I pulled my "Field Fix" apart, and the alternator was working fine?

Did my brushes get hung up???