This 2004 Suburu Outback needed a new alternator. So I goes to the nearest Auto Zone and gets a brand new Duralast, and puts it in.
What a waste of time. I think it had a shorted winding - it was whining like nobody's business and it got scalding hot within a few minutes of running mostly at an idle, pushing around 30A at an idle, up to 60A at higher RPMs for short periods.

I took it back right away, it was still so hot when I got it back to the store all the clerks had to touch it and see, it was funny.

I did try unplugging the field power wire on the alternator and the whining sound instantly stopped completely (ha and the engine sped up) so I know it was the alternator making the sound and that it was really pulling hard even when it wasn't pushing a lot of current.

Then I got some other brand from Napa and put it in, and it never got above boiling -- and it was pushing 90 amps after an initial 112a quick charge when the engine was first started.. It actually whined some too at 112 amps but not as bad as the Duralast did at 30A...

Ironically the Napa part was same cost and also had a lifetime warranty.