Alternator AC DELCO or OEM Mazda

If those are your only options you're gonna go with, Remy or ACDELCO. Keep in mind the ACDELCO is not made by ACDELCO and is just rebranded. But has a warranty and decent support.

I was able to remove/replace the alternator on my Mazda CX-5 without removing any parts as has been mentioned.

I always get AC Delco from RockAuto... never had one bad out of the box... Can't really speak to any other brands.

Please, genuine alternators are only like $30 more and you won't suffer these issues. And also they last.

I\u2019ve had an ac delco alternator from rock auto in my Honda Fit for 7 years now.

I went and got a Mazda one off of Moss bc I was sick of AutoZone remanned ones blowing up. It's plenty nice for stock electrical load

Got some faulty alternators from autozone that were overcharging or undercharging. I just bought an oem reman from mazdaswag, (or any mazda dealership store online). Works fine now.

Have been burned by aftermarket alternators. I'll spend the money for an OEM every time.

The issue you can run into is most common vehicle alternators are light duty at best. Lets say its a 100 amp alt, don't pull more than 40 amps continuous. A great example is the AC Delco 10si alternator. Loads of cheap knock offs and copies of that alternator all claiming crazy high amperage but none list the duty cycle. The 10si frame is designed for 40 amps of power and the heat that creates. You might be able to get a little more cooling with a better fan but you won't get 100+ amps out of one.

I'm surprised Mazda is rated so poorly, I had a Mazda MPV for 8 years and honestly the only problem I had was the driver's side window gear was worn out, and the alternator.