Alternators seen to go bust around the 15-20 yr mark from my experience and friend's cars.
Good thing you decided on a new one since it has warranty. I bought a reconditioned one and failed in a few weeks...
One of my mechs sources alternators from UNIPOINT (manufacturer), run about $320 through him but it's quality stuff

Got car back yesterday, all good.  Mechanic that replaced alternator wanted to check that battery is charging ok.  Yep all good.
He has one question tho, just to cover all his bases, so that when he sends the alternator back to his supplier he has all the facts.
build date is 7/90. I'm sure someone on here can answer the question.
He has asked if the regulator is internal or external.

Internal.
 
 
Tell him to check the smoke seals . . . .
 
 

Thanks Dennis

dennis the menace
Internal.
 Tell him to check the smoke seals . . . .
 

LOL. I was gonna say, if the mechanic cannot tell the difference, it's time to find a another mechanic...
But you know, if you've got nothing nice to say, don't say it

Knightrous

LOL. I was gonna say, if the mechanic cannot tell the difference, it's time to find a another mechanic...
But you know, if you've got nothing nice to say, don't say it

Strange. The exact same thing crossed my mind.

He isn't my regular mechanic.  When I had a problem with the alternator 4 months ago, I took her to the Auto Elec that was in the shed next door to him.  He did the Auto Elec a "favour" and put her up on the hoist to take the bits off to get to the alternator.  The alternator ended up being replaced instead of fixed.  So the auto elect ended up doing nothing.