Alternator Question?

[99gatorbird]

I have a 99 V6 firebird, 5-speed. I went to Autozone and this guy hooked up my car to their machine the Alternator was putting out 13.5-14.2 volts, and the peak amps was like around 6. He was like your alternator is bad because it should put out like 100 AMPS. Well their alternators were to expensive so i waited about a week, while my volt meter on the dash was fine stayed above 13. So i went to Advanced Auto and bought their ALT. for 90 dollars. After i put it on my car brought it up their to have them check it out. Well the new one was like putting out like 13.5-14.2 volts and the max ampage to the battery was like 12. Well we did about 2 more tests each test and the ampage was 7 and 10. Well we tested the old alternator on the machine on the inside of the store, it tested fine. So i got a refund on the one i bought and put the old one back on, we tested it again. The old alt tested 13.5-14.2 volts and about 11 amps this time. My question is did the original guy at autozone not know his machine to well and just want to sell me an alternator. I have read that these firebird alternators can hold up 100+ amps. Is this true. Does it sound like my old alternator is still good? Its a Delco on there now, i assume it is the original. Does anyone know about this? Thanks for all the help

[OneQuickV6]

I work at Advance and can tell you that if the guy at Autozone used the portable tester to check the alternator ON your vehicle, the current readings are wierd. They are NEVER as high as is actually being output. The tester in the store is the only idiot proof test for the people that work there, the portable one is good only if you know how it works and how to read its results. Moral of the story, know which people at your parts store know their shiznit, and always ask them for help, if they aren't there and you can wait, come back when they are there.

[youngcamarokid]

You're getting the two things mixed up. First of all, an alternator does not SUPPLY a FIXED amount of amperage (amps).

The amperage rating that was taken is how many amps the battery, or whatever the load was, was DRAWING from the alternator.

The rating of the alternator (100A) is only the maximum amount of amperage the alternator can supply before a burn-up of the internal coils.

The guy has no clue whatsoever about anything relating to alternators, and he probably learned how to use the machine two days before you went to the shop.

The only thing an alternator SUPPLIES is the voltage. Obviously, the voltage will be higher at no load (just running the battery-charging circuit) than when it is powering the headlights, wipers, stereo, and whatever else you might have hooked to your car.

You don't need a new alternator unless your lights dim at a stop light or your battery goes below 13 or so. Please don't let anyone talk you into one....**** jack***es :mad: :mad:

[99gatorbird]

<blockquote>quote:</font><hr>Originally posted by youngcamarokid:
You're getting the two things mixed up. First of all, an alternator does not SUPPLY a FIXED amount of amperage (amps).

The amperage rating that was taken is how many amps the battery, or whatever the load was, was DRAWING from the alternator.

The rating of the alternator (100A) is only the maximum amount of amperage the alternator can supply before a burn-up of the internal coils.

The guy has no clue whatsoever about anything relating to alternators, and he probably learned how to use the machine two days before you went to the shop.

The only thing an alternator SUPPLIES is the voltage. Obviously, the voltage will be higher at no load (just running the battery-charging circuit) than when it is powering the headlights, wipers, stereo, and whatever else you might have hooked to your car.

You don't need a new alternator unless your lights dim at a stop light or your battery goes below 13 or so. Please don't let anyone talk you into one....**** jack***es :mad: :mad: <hr></blockquote>


Hey dude can i email you with some more questions?just hit up the email on your profile?

[silvachris1]

As I posted in your General Tech topic:

<blockquote>quote:</font><hr>Originally posted by silvachris1:

The best advice I can offer you is to stay away from the alternators from Advanced Auto. My original started making a whine and a tick sound, and then eventually quit charging. I gave up on it and gota new one (prolly a remanufactured one ) at Advanced Auto, and it wouldn't charge but didn't whine or tick. Took it back to a different Advance store and they replaced it. This alt charges, but makes the same whining and ticking sound my original did before it died on me. So the next day, I drove 40 miles, to the next closest Advance store and again replaced the alt, hoping to get a good one. This one didn't charge (or make any noise)so I put on the previous one that charged but whined. Then I went about 20 minutes to the next little town with an advance and went through the same process again, only to get the same result, no charge but no whine or tick sounds. Then put the only one that would charge back on. This whine and tick sound is so aggrivating. Finally dad went to the local Advanced Auto and got another one after they ordered it (a week ago) and installed it. He said it is charging and he doesn't hear any noises. Grrrr, if I get home this weekend and find out that this thing is making all kinds of crazy racket, I'm gonna raise some serios trouble. Of course they said if this one doesn't meet my satisfaction, they will refund all my money, including the core charge. I will never ever buy another thing Advanced Auto Parts unless I have no choice.<hr></blockquote>

So, if anybody has a cure to my problem, please let me know. All the Advanced Auto Parts workers around here are either seniors in High School and have no clue what they are talking about. And the rest of them don't know a thing about how the charging actually works. One guy told me that the Alternator was supposed to whine, that meant it was charging. Grrrrrrrr :mad: And my local dealership, well, they want $400.00 for a brand new one. [img]graemlins/omg.gif[/img]

[OneQuickV6]

<blockquote>quote:</font><hr>Originally posted by youngcamarokid:
The only thing an alternator SUPPLIES is the voltage. Obviously, the voltage will be higher at no load (just running the battery-charging circuit) than when it is powering the headlights, wipers, stereo, and whatever else you might have hooked to your car.

You don't need a new alternator unless your lights dim at a stop light or your battery goes below 13 or so. Please don't let anyone talk you into one....**** jack***es :mad: :mad: <hr></blockquote>

Dude, before you start throwing words around like they are the new 10 Commandments, take a EE course or two. An alternator is the root of your car's AC electrical system, yes AC, alternating CURRENT. Although it does make your voltage gauge show 13 volts or whatever it reads, it is actually a generator of current. Good job. Look up Ohm's law sometime, and quit feeding people false info.

Just a note, yes I also know the car's accesories run off DC, but your alternator is actually producing AC current, hence the ALTERNATor part, rising and falling.

[youngcamarokid]

Actually I have taken EE courses. And yes the alternator is producing AC current, and in case you didn't know it then passes through something called a bridge rectifier. This makes our sine wave of -13.7 to 13.7 peak-to-peak into a positive only 13.7 wave of double the original frequency. Then this supply voltage is still AC. It is fed through a regulator or a large capacitor to filter this AC into DC.

None of my information is false info. What I'm saying is the amount of current coming out of the alternator is dependent on the load placed upon it. Unless you have .137ohms of resistance on the alternator, you'll never get a reading of 100A (that's assuming a 13.7V supply voltage).

An alternator does not automatically "provide" 100A, it just has a maximum rating telling how much current your circuits can draw from it.

I know what I'm talking about, and yes, 99gatorbird, you can hit me up at my email if you wish.