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

 

I don't think he was working his machine to well. For the alternator to be under full load it will reach about 100+amps but you're car wasn’t taking up that much power at the time. Say if your battery was completely dead or you had a short somewhere, the alt would try to put as much power out to that single point just to keep the voltage level at 13-14v. That’s when you would be getting high amps. but hey, I never used one of these machines and this is just a logical guess... I could be completely wrong. From my understanding of how they work thats what I would guess happend.