If you got that alternator at Autozone, odds are that most of your problem is there. When I worked for them, I got to where I would bench test the new ones before completing a transaction for my customers. Drove the manager crazy, but I did catch a few bad ones out of the box that way. I had a lot of upset people when I quit working for Autozone. The told me I needed to come back. LOL I told them they couldn't pay me enough to come back and put up with the sorry manager and assistant at the store where I was.