hello my battery went dead the other day had the car tested battery was good but the alternator was puting out 39 amps at a idle is this good or not the guy at autozone didn't think so. He thinks it is going bad and they dont stock one at all so he was not just tring to make a sale.
thank you all for any help

 

39 amps at idle is not bad if everything was turned off.
Since you have a new Monte and if the alternator might be bad.....
Take it to the dealer have them test it. It should be covered under warranty

Have them do a proper load test on both the alternator and the battery...

What made the battery go dead?
Has the car been sitting for a while?

 

no I was just wanting to go to work with the stereo on about 10 min then I saw the headlights were on turned them off tried to start it and it was dead

 

How many amps is your stero pulling from the alternator?

As stated before 39 amps at idle is not bad if it was tested with everything off. If however you are only pulling 39 amps with lights ect turned on and the engine is running between 1500-2000 grand then yes I would say the alternator is bad. Again I would take it to the dealership. If the alternator is bad they should replace it under warranty. If the battery is bad and the car is over 1 year old then they will pro rate the battery.

 

I need to test it

 

should test voltage...not amperage...thats the easiest way to tell if something is bad...

do you know what the voltage on the battery and alternator were?? 12 is not enough...its a 12 volt battery..but it must be 13(at least) to start the vehicle..and when the car is running the alternator should be putting out around 13.6-13.9 volts
if its not then you have a bad alternator, if it is then check the battery again...make sure terminals are clean too