alternator out or no?

alright guys, so i took my alternator out today after my car died a couple weeks back. when it died on me all that was happening was the lights kept getting dimmer and dimmer and then it just lost all power. weird thing is that the next morning i went to bring it home and it started and drove almost home before it started surging and barely made it back. i was driving with the headlights off this time since it was light out. but i'm not sure what explains this. i went ahead and bought another alternator from a guy on here and its on the way. turns out its JDM and my car is USDM, so is that going to cause issues? i am fine splicing wires but i don't know where to get the right connector. and lastly, i test the alternator i took off the car today just to verify that its bad, and at autozone it passes. twice. i'm not sure what to think now, but any advice on any of the above is greatly appriciated. thanks!

the jdm will plun in play ,sounds like the alt is bad i wouldnt trust auto zone

It could be a bad ground. I had a similar problem in that my lights were dimming at nite so I changed the alternator but made no differance at all. If you have a volt meter check the amps coming from the alternator and the battery as well and start chasing down the ground wires.

new alternator- everythings fixed. i don't trust autozone, never have. lol. thanks guys.

see like i said auto zone sucks

Early stage alternators can charge and then not charge when they heat up before they crap all together ... cant always trust those in store tests ... I've had the above happen at least twice on my own alternators ...