I recently rebuilt my 2.8L in an attempt to help it pass local emission standards. Just before the rebuild I replaced the alternator with one from AutoZone. Seemed to work fine, but I didn't drive it a lot after the replacement. Maybe 35 more miles. I am now tuning everything from after the rebuild. At about 110 miles on the new motor the alternator completely failed, and I got a warranty replacement from AutoZone, which I installed last night. This morning I drive into work and when I get here instead of a nice 16 on the volt meter in the car I am at 14. I will check again at lunch or something, when the car cools down, but has anyone else had this with burning through alternators?

My previous 86 GT didn't ever have an alternator issue, and always got great power.

16 on the gage is quite a bit.......

quote Originally posted by olejoedad: 16 on the gage is quite a bit.......

Maybe part of the issue is that I don't know the gauge. 13 Volts is straight up and down. At the far left, beyond the, red is 8. The far right, beyond the red, is 18. There is a line just before the red on the right and that is where it normally rides (in my 86 GT and this morning in my 87 GT). Am I way off here?

The stock fiero volt gauge is know for its inaccuracy. The only thing I use my stock volt gauge is for is a reference. You should check the actual voltage with a good multi-meter. The voltage at idle with no electrical accessories running should be between 14.1-14.4 Have you had your battery load tested? If your battery is no good that will kill a alternator quick. The alternator is not designed to be the sole source of power for the car. Its only meant to top off the battery and keep it charged.

Beaten to it. Mere seconds...

Stock gauges are notoriously off. Use a volt meter at the output of the alternator. You want approx. 14.5 volts.

[This message has been edited by Tony Kania (edited 08-01-2013).]

You don't say what year your 2.8 is, but are you using the factory heatshield on these replacement alternators? If not, maybe you're cooking them.

quote Originally posted by Patrick: You don't say what year your 2.8 is, but are you using the factory heatshield on these replacement alternators? If not, maybe you're cooking them.

The 2.8 is out of the 87. I don't remember taking a heat shield out of the car when I rebuilt it. And I don't have any parts left over in the garage. What does this heat shield look like?

quote Originally posted by undertakingyou: I don't remember taking a heat shield out of the car when I rebuilt it.

I suspect that means you didn't install one then.

You absolutely need to use an alternator heat shield on '85-'87 Fiero 2.8 engines. Otherwise the extreme heat from the very nearby rear exhaust manifold just cooks 'em.

[This message has been edited by Patrick (edited 08-01-2013).]

Yep, I definitely don't have that heat shield. I would have remembered it on the old alternator too. I bet the guy that sold it to me just didn't have it. Having never replaced the alternator in the 86 GT I had I had never seen it (or paid attention to it). Now, the better question, where can I get one of these?

quote Originally posted by undertakingyou: Now, the better question, where can I get one of these?

You can try the Mall here.

I got mine from the wreckers. The whole alternator, including heat shield, and mounting bracket (which often breaks) was $17.95. That's a great price.

[This message has been edited by Patrick (edited 08-01-2013).]

Just did an inventory check at local wreckers. Not seeing anything. Let me ask you this, it seems like the only difference for the 88 motor is that GM moved the heat shield from the alternator to the manifold itself. I can find that part number and could order that heat shield. Any reason that wouldn't work?

quote Originally posted by undertakingyou: ... it seems like the only difference for the 88 motor is that GM moved the heat shield from the alternator to the manifold itself.

That's not quite correct. The alternator is different as well. Among other things, it has a more efficient built in fan.

You'd be better off to get the proper heat shield for what you have there.

Is there anywhere on your heat shield that it shows a part number? Maybe I can get it still.

quote Originally posted by undertakingyou: Is there anywhere on your heat shield that it shows a part number?

I'm not taking it off to look for one.

quote Originally posted by Patrick: I'm not taking it off to look for one.

Well ... Can't blame you. I don't see one in the pictures either. Oh well, worth a shot.

I have one that you can have. Is from an 87 GT but is the same heat shield. PM me your address and I'll get it to ya.

~James

I love this place.

quote Originally posted by Tony Kania: I love this place.

Amen. I am nearly overwhelmed by the kindness shown here. I don't know why I didn't use the forums more when I owned my last Fiero.

Thanks James!

Anytime. I've had people show me the same kindness here in the past while I had my last Fiero and was still in High School 12 years ago. Although I dont assume thats your situation, lol... I am glad to help.

~James

Edit to add... did you receive my texts?

[This message has been edited by EvilSqueezles (edited 08-01-2013).]

quote Originally posted by undertakingyou: I don't know why I didn't use the forums more when I owned my last Fiero. Thanks James!

Geez, throw me a bone here.

quote Originally posted by Patrick: Geez, throw me a bone here.

ε>=<3

Bone thrown. Thanks man.

<3 Patrick. Good call on the heat shield.

~James

quote Originally posted by undertakingyou: Thanks man.

That's all I'm after.

Don't mind me. I'm just feeling sorry for myself because I screwed up my trusty '84 duke. I added shims to the rocker bolts (as per This thread) and suspect I've burned an exhaust valve. <sigh>

Alternator output should be in the 13 to 14 volt range depending on temperature.
Get a voltmeter that plugs into the cigarette lighter socket, it is usually accurate
enough, and better than the Fiero voltmeter.
With the engine not running the voltage will be 12 volts +/- a volt depending on
how long it has sat.

USPS says it should be there Monday. Tracking number is :

9505 5214 4071 3215 0001 12

USPS.com to give her a check in. Hope that fixes your problems. Take care.

~James

Also make sure the fan in the trunk is working. It comes on whenever the rad fan comes on and its purpose is to supply a constant stream of air for cooling purposes of the alt.
Mine used to do the same thing with everything working in order. My solution was to replace it with a different design with a bunch of amps, 220 to be exact!
I don't need that much but that alt has also other upgrades that for what I use my car for it is just perfect.

http://www.powerbastards.co...ducts.asp?cat=135524

Good luck mate!

[This message has been edited by La fiera (edited 08-04-2013).]