Hi i put about 15 new alternators on my car this year and im taking it back again today (it was under warranty). They just keep going out for some reason. I had an diagnostic done and the car is fine but every now and then it goes out. Could someone help me find out what the problem is.

Sure you have the right alternator for your car? In all of these changes have you replaced the battery? Who makes this alternator?

Yea its the right one i got it from autozone and they look in the computer for it so it has to be the right one. Also my battery is an diehard is it works wonderful almost brand new

Do you have any aftermarket electronics in your car?

nope!

Hum, if you had aftermarket electronics, you would need a larger alternator. You may have some type of bad ground.

I agree,a bad ground could be the culprit.The ground is typically made thru the alternator housing so make sure the mounting bolts and bracket bolts are clean enough to make a good connection to the engine .Also check both ends of your negative battery cable .And last but maybe most important is the very real possibility that Autozone is still selling crap .Myself and too many others i know will never buy Autozone alternators or starters and most of their other parts either.Especially a cheap one.Do yourself a favor and get an AC Delco Remanufactured one.Their should be a parts store that carries them so you don't have to get one from the dealer.Don't be fooled by cheap price and the lifetime warranty.I'd rather have a quality part to fix the job the first time than an unlimited supply of junk.Especially when it lets me sit and I gotta change a starter again in the middle of winter but hell I saved 20 bucks and they'll give me another one.Not picking on you and don't mean to preach but I've seen this too many times.PepBoyz most expensive totally new never rebuilt alternators only last about 2 years but they have lifetime warranty also.Go AC Delco,they have to be reman to GM '* standards.

AC Delco all the way!

ok thanks i hear what your saying because i also have a 94 Mercury Cougar 4.6l and i bought an powersteering pump for it from Autozone. Yes they gave me a LIFETIME warranty but the dam thing went out 7 days after i had paid a mechanic 125 dollars to put it on. I wont be driving that car for a while, lucky for me i can do my own alternator on my bonnie. But i think ill try the Ac Delco because i have their high performance spark plug and im killing anything that races me (V6 only). But thanx alot guys!

AC Delco has some good stuff but may not always be the answer to a problem. I was on the third alternator when the warranty ran out on my 96 model. When that alternator died I took it to an alternator & starter repair shop and asked if they could put in a heavy-duty diode bridge. The owner of the shop said that was usually the problem with late model GM alternators and that he only used heavy duty diode bridge’* to prevent come backs. That was over two years ago no problems yet knock on wood.