so i have a 02 pontiac bonneville wiht 97000 miles. Took the car to pepboys to have them take a look at it before i went out for a road trip this week to NC and they told me 1) the battery was bad and 2)alternator was going bad

So they told me the cost for both with labor would be 500 out the door. Of course i declined because the alternator on this car 3800 series 2 motor is cake as well as the battery. I didnt believe them so i went to autozone and had both tested. Of course the battery was bad so i had it replaced. The alternator is good. Well i just wanted to make sure the battery after i installed it read fine. I bought the battery at walmart. Went to autozone again and said the alternator was good and the battery was bad. Hmnm, idk what to do now. So i went to walmart service center and had them check it. Did it for free and they said the cranking amp was around 600 and supposed to be at 770 CCA. So they recharged it and now its reading 15.07. But i dont know why they need to recharge it if th ebattery is only a day old. Well im leaving to go out of town and this concerned me because i dont want the alternator to go bad when im going down to NC. I trust the tester i guess saying the alternator is good.

You will want to check both ends of both batter cables for corrosion. If they corrode the amps drop fast. Clean them up and reconnect. then test again.

they seem to be ok. But that doesnt explain them telling me the alternator is bad? Would u reccomend changing it? I had it tested 3 different times at autozone using the handheld tester and it all said it was good

Depends on where they connected the tester. We have seen the cable corrode under the isolation. There are several tests in the tech info area that cover this area. Take a look and see what you find.

so i jsut went ahead and replaced the alternator. I figured it was reading to high at 15.07 it was overcharging so people have told me its the voltage regulator inside of the alternator thats going bad. So i just went ahead and replaced it. Im going out of town in 2 days and i dont want to break down in the mountains.

Hey Armin...I understand. Better to be safe than sorry.

yup yup thanks alot for everything guys!