I replaced my alternator with a new one from autozone. They tested it at the store and it was good. I installed it and the next day it was bad (no output). I returned it for a new one, installed that, and same thing happened.
I already replaced the battery, and had the wiring looked at.Nothing wrong with wiring.

Could there be anything causing the alternator to go bad? Or am I just getting junk alternators??

Please help

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Did you unhook your battery when you install them?

yes , unhooked battery during installation, belt is tight, all connections good.
I have done this twice now.

quote Originally posted by bigpacupacu: yes , unhooked battery during installation, belt is tight, all connections good. I have done this twice now.

all of the connections could be good but you could have a bad wire somewhere. this may be why your first alternator went in the first place. If i were you i would start testing wires.

good luck, i hope this helps you out
-Phil

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86 SE V6 under constuction
Rate me if i am of assitance please, thank you...

I had wiring tested. nothing wrong there.
Is there anything else that could be killing these alternators??

I am really confused about the whole thing.

i think you're just getting junk alternators because i was at autozone to exchange my alternator (which i bought there) and both alternators which they had on the shelf, both tested bad on their machine. And currently my alternator is squealing like crazy. The alternators that they tested, 1 was rebuilt and 1 was new, both were bad.

-Coop

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" -Hey mom, can i get some ice cream?
-No Dice
-This aint Ova"

Thanks,
I guess I will get another one and try it one more time. What a pain!

Well, I have just installed my 4th alt and still having the same problems. The only thing I haven,t checked is the fuse to the dash light. Can anyone tell me where it is?
Plus, is tha alt light and the batt. light the same? Everything else checks out fine, so somewhere along the brown wire from the alt to the light has to be the problem. I think. But where is the fuse?

Yes, the alternator light is the "battery" light.

I don't know how you "tested" the wiring but I'll be very surprised if there are no wiring problems.

Read Wire Service in my cave for a start.

You have to physically inspect every inch of the alt harnes wiring, the battery cables, and the various other grounds in the engine bay. All it takes is for the alt wires or the + battery wire to arc just once to fry the alt. Odds are really good something is rotted or rubbed bare and having a short only under certain conditions as the car bounces around.

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No good ever came from dark and spooky. Norville "Shaggy" Rogers

The Ogre's Fiero Cave (It's also at the top of every forum page...)

Similar deal here... I just put in a new one tonight, as my old one was grinding (bad bearings, I assume, because it still charged)... After not quite, five minutes of driving easily around a residential area, even louder groaning and whining... UGH!

Nic

I find that the Lifetime Replacement Warranty thet AutoZone offers gaurantees that I will be replacing the part every year for free for the rest of my life.

quote Originally posted by Carrolles: I find that the Lifetime Replacement Warranty thet AutoZone offers gaurantees that I will be replacing the part every year for free for the rest of my life.

That's strange, I checked into buying an alternator (88 2.8) from Autozone last week. The guy at the counter got a funny look on his face when he pulled up the alternator number on his computer. He said "that's weird, this shows we only offer a 1-year warranty on this alternator". But almost every other alternator they sell has a lifetime warranty! I passed on buying it and was going to look into another place to buy one.

Well, I am going to let someone else try and find the problem . A real mechanic with the proper tools.
I'll tell you what though, I am getting pretty good taking out and reinstalling these alts. The last one only took under 15 mins. to take out and put another back in!

which alt do you have?

I got lucky. I changed my alt and was driving around and noticed the car seemed to go dead for a split second once or twice. I thought "oops" what did I do now? I looked at the alt and saw that my wires were hanging low enough to rub on the drive shaft when I hit a bump. I looked at the bottom of the wires and they were worn through. I checked the wires to make sure they would still work then taped them up and dressed them out of the way of everything. No problems since then. I just don't know why the alt did not fry?

snoopy... 5 points for dumb luck...

I don't know what you taped up the wires with... If you used common electrical tape and it's been awhile, take the tape off and check for corrosion.

All...

After you've fixed any damage, rewrap the Clean wire with self sealing/curing/vulcanizing tape. (It goes by various names.) This tape will fuse into a solid mass over the repair and won't let water in like regular electrical tape will when it get's loose. You can get this stuff at radio shack.

You can also use self sealing heat shrink over a splice. Or pack a joint with silicone and use regular heat shrink. Anything that will keep water out.

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No good ever came from dark and spooky. Norville "Shaggy" Rogers

The Ogre's Fiero Cave (It's also at the top of every forum page...)

My car is fixed!! I had another shop go over everything again and still found no problems with any wires or connections. So they put another alt in from a different store and that seems to take care of the problems. I got all four of the alts from AutoZone and they were all junk! I couldn't believe it. 4 alts! Even got a better one the last time.Needless to say I won't be buying any parts from AutoZone ever again. What aggravation!!
Any way, the new alt is in and has been running great for two days now.

Thanks for all the info and suggestions everybody. Much appreciated.

Steve

quote Originally posted by theogre: After you've fixed any damage, rewrap the Clean wire with self sealing/curing/vulcanizing tape. (It goes by various names.) This tape will fuse into a solid mass over the repair and won't let water in like regular electrical tape will when it get's loose. You can get this stuff at radio shack.

Ogre...thanks for the tip. I had never heard of this stuff. Sounds like something to pick up and have on hand. The other thing I can't stand about electrical tape is the gooey mess you get when trying to remove old stuff. Yuck.

Was your battery fully charged when you installed each new alternator? A battery that is only 80% charged can kill a new alternator.

Yes I always fully charged the batt. before installing a new alt. I thought it could be bad alts, one maybe two, but not four! but they were all crap. AutoZone sucks!!

I was having a bad round with Pep Boys Alts in my 85 GT. Replaced the orginal with a Pep Boys Alt and in 2 months had the rear bearing (near the manifold) disintegrate. Replaced it and in 2 months the engine spun a bearing but not before the rear bearing on the alt started to disintegrate....

I could either be replacing alternators every two months or I can try and protect an inferior alternator with a heat shield from an 88 (altered slightly) or I can just pop for another alternator. I find that its at the little ma/pa stores that seem to have the parts that I need! Anyone else have that experience?

I bought a *new* alternator from Pep Boys. Sold under the ProStart brand, and came with a lifetime warranty. The price was around $119, which was not much more than the other stores were getting for rebuilds. Only trouble was, it wouldn't fit.
The holes for the pivot bolt and adjusting bolt were 1/16-1/8" too close together. I couldn't get the adjusting bolt to thread into the hole, as it was misaligned with the slot in the bracket.
Ended up taking apart two unusable alternators and building one good one. What a pain.

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Raydar

88 3.4 coupe. 17s, cut springs 'n all.