Need help immediatly!!!! My 01' Firebird Formula keeps blowing alternators! I have an 8 month old Optima Red Top under the hood and have blown 5 alternators in the past 2 months... I ran a new wire from the alternator to the PCM, ran an extra ground from the body to the engine block, replaced the PCM, replaced the alternator and put the red top under the hood. I do not have any kind of sound system other then a 5 year old Pioneer in dash tv head unit. Only other aftermarket electronics on the vehicle are o2 simulators and an SLP mass air flow sensor... This problem has my whole shop of GM techs baffled! Any help would be much appreciated!

 

What do you mean blowing out alternators? You're actually burning them out?

 

Yes they keep burning out, I'll just go start my car one day and notice the voltage is back to 10.5 11ish area and no charge ouput from alternator...

 

Are you using reman alts, or buying them new? If reman, then you've just found out why I only use new ones.

 

are you sure your battery is ok? it sounds like your alternator is constantly overcharging the battery

 

They're Reman's but genuine AC Delco ones and we NEVER have problems with them in any other car we use them on. And the battery is an Optima Red-Top thats only 8 months old, I have tested it 4 times with our GM battery tester and you can een select absorbant gas mat and spiral cell on the options and always comes out as a good battery!

 

it sounds to me like there is a drain somewhere in the car, so its putting excess strain on the battery, therefore putting a lot of strain on the battery. but when its that fast im not sure what to make of that. try a different brand of alternator and see what happens

 

How long does it take till the newly installed alternator burns up?

Why did you run an "extra" ground? Unnecessary.

Just curious...is there any power steering fluid dripping onto the alternator? Very common when people keep burning up alternators.


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I've already had the genuine AC Delco reman's and they wouldn't warranty any more so I went to Pep Boys and bought on from them adn that lasted a month (compared to a week or so on a Delco) and thats the one that burnt out last week and now I got Pep Boys to give me another...

 

I figured just to rule out that the block didn't have enough ground or a good ground I would eliminate it with an extra ground run... And nope, no power steering leaks at all!

 

I would put a new positive battery cable on the car.

 

Not a bad idea. I have seen the positive cable, inside the rubber coating actually "break". It snaps like a twig and its in two pieces inside the rubber coating. You can do an alternator test while its in the car running and then you grab the red positive cable and move it around from the top and from the bottom and see if the readings spike up and down sharply.

Don't know why that would burn up an alternator though. Maybe it kills the voltage regulator in the alternator.


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Yea I thought of that myself and put a whole new positive battery cable in the car when I put in this most recent alternator last week. Cable seemed fine but I figured why the hell not... I think next step I am gonna try to sell the Optima Red Top for 100 bucks (only 8 months old) and put a genuine AC Delco back in there...

 

changing out the optima would be a waste of time and money.
If it starts the car fine, and if you check the voltage on it after it's been sitting 24 hours and reads greater than 12.50 volts then it's fine. The only other test you could do on it is a load test, but be careful who you have do the load test. If you bring it to autozone, pepboys, or someplace similiar, they typically don't know what they're doing, all they know is red positive, black negative, push button on machine. The load test will put a draw on the battery half of what the cold cracking amps is for 15 seconds. The red top for the f-body is 75/25 (8022-091) which has 720 CCA so the load test should pull 360 amps for 15 seconds, and the battery voltage during that 15 second should not fall below 9.7 volts at 80F, and 9.5V at 60F ambient temp. And you can only do a load test on a battery that has near 100% state of charge, if it's less than 75% or voltage across the terminals is less than 12.45 volts then the battery is weak to begin with and should be charged first. Hopefully after all the times the car ran without the alternator charging you have put a charger on the battery.

Aside from that, find out what's actually failing in the alternator.
http://www.aa1car.com/library/charging_checks.htm
http://www.genco1.com/tech_tip_details.cfm?id=86

After you start the car and see < 10v on the gauge, do you pull the alternator and check it on a bench to see if it is actually failed? If not, you may just have a faulty field connector that plugs into the alternator which is loosing it's connection over time. I thought i've read here that a lot of guys have found that connector to fail.
Otherwise, if the alternator on the bench test does not charge, then check to see if any of the diodes in the diode trio (rectifier) in it has failed, if so then that's most likely caused by voltage spikes in the system which are most likely caused by a bad battery cable somewhere- possibly the + cable at the battery... if that connection breaks for a moment then there's no load on the alternator and it will produce large voltage spikes which in turn burns out the diodes.
Aside from that, another check is to put an ammeter on the alternator output terminal, in series, and measure the output current. If the output is upwards of 70-80 amps with normal accessories on (headlights, stereo, heater fan) at fast idle then it's possible it's being overloaded and failing from overheating.
And you may also try a full field test on it as described- http://www.balmar.net/Page64-troubleshooting.html

http://autorepair.about.com/cs/elect.../aa122700a.htm
http://www.autoshop101.com/trainmodu...or/alt101.html

 

Yea I've load tested the battery here at my shop and it comes out good, and with all loads on in the car the alternators putting out 76 or so amps and 25 at idle so I know thats all working properly and with this most recent alternator I also replaced the positive battery cable so i guess time will just tell if this damn thing blows again!