I got an auto zone alternator....it works, but randomly.

Haven't had to jump my truck YET...but I can tell by my dash lights when its actually charging.

EXAMPLE: This morning I left for work with dim dash lights. 15 miles later I pull into work and let it idle for a few seconds and BAM! Idle dropped and my dash lights got super bright. Revved it up a bit and sat for a couple mins for some charging action. Turned it off and got on TM, lol.

Its been a few months, so its working often enough.

Safe to assume its the internal voltage regulator?

And does anyone sell the part?

I don't want to gamble with returning it, if I can change out 1 component and have it last as long as it SHOULD.