Dead Battery Again

My new battery just died again, the last one about six months ago. While driving the windshield wipers started slowing and down and when they were running the car started jolting, missing and eventually stalled. The battery was completley dead. I'm assuming a bad alternator, but I had a local auto parts store check it about six months ago when the last battery died and they said it seemed to be a little low in output but should be OK. Isn't 6 months a long time to go on a bad alternator. In addition the vehicle stalls now when coming to a stop after running for about 15 minutes, but after being restarted it runs fine. And one more thing, I hope this is all related, the check engine light has been on for about two years now. I had the local GM dealer check it out, he got it to reset but it lit back up again after a few minutes. They said it seeme to be related to the heater in the car and shouldn't be a problem if I just ignored it. Any ideas??

your heater will not cause your check engine lamp to come on!!!!! I
would check my alternator to make sure it is charging properly. It should put out between 13.9 to 14.1 volts. have your code for the cel checked while the alternator is being checked.

Do my problems sound like yours?
I stalled every time I slowed down the RPMS to stop or shift gears on one day and one day only. It hasnt done it since. It doesnt want to start, it is turning over extremly slow and takes about 1-2 minutes of slow reving to finally turn over. (sorry I dont know how else to describe the sound) It is a slow the-battery-is-dead-but-it-still-might-start-sound. It starts out really slow then gradually increases until presto! It started!
Some days I get in and it does absouletly nothing. No rev, rev, rev, turn over. I wait or push start it ( thank God for a stick shift ) and then it is fine.
I do have a belt that is sqealing, it was recently replaced. It doesnt squeal all the time though. It will usually stop after I change gears, or stop.
I also have a check engine light on. The previous owner had that checked out, they said it was an oxygen sensor. Anybody know what the deal is?

I would take it and have the charging system checked out. It may also be a starter problem.... Have the code checked for the check engine light, and go from there

http://www.jhodson.net/miata99/drain.html

try my doc. on finding this problem.

Quick test for the alternator... Start car, turn on all lights and accessories. unhook the positive from the battery if the car dies its not getting enough juice from the alternator.

viPHER H , THAT IS A before electronics , was invented test.:banghead:
back in the days of Desoto , 57 chevy, etc.

Never ever run the with an open battery.

The FSM in almost every single case , warn of this.
RTFM.

same catagory as grounding things and applying 12dc from battery to things that connect to the ECU. ( look first , get a print)

:screwy:

Ive been an electroncs tech since 1965 and you guys are made me rich.
thanks for that.
now I try give back. ( many mechs would never say this, cuz....)


for those that insist , please disconnect all the main ECU and ,
and if you have others , those too, Power train, tranny , body, Flyby wire box, on your Chev, or any others like the Tail light ECu in the grand cherokee.
you could do $5000 of damage on that last car.


these parts are designed to work up to 14.7 volts (a tad more "guardband"l)

nothing more. ( never transgress in to gaurdband , unless rich)

the regulator will go crazy with no load on many a alternator.
which one or kind is on your car , who knows.

I place this here so others can save their , behinds.