Car drainning battery then dies!! WTF??

[Teele]

I have a 94 Camaro with 170,000 miles. Ok, a few days ago, when i was driving, my battery wouldn't charge off the alternator and it slowly drained it till it was dead and my car died. Well, i got a new alternator and put it in. I also had the battery charged and tested and they said it was good. I put in the battery and it ran good last night. The volts were at 14. I went out this morning and started it up, the volts were now at the mark just past 8. Well on my way to school, I watched it slowly drop. I new it was going to do the same thing it did the other day so i turned around and headed home. It was backfiring after shifting from 1-2 and from 2-3. Then the SES light came on. Right as i turned on my street, it died and I slowly coasted to my house. What is going on here? I had the battery tested and charged and they said it was good. I just put in a new alternator, could it be bad? Please help. I have put over $500 in this car in less than a week! Thanx in advance Teele.

[3.4 slow to go]

are the cables good, and is everything hooked back up?
You might have a short/draw somewhere draining the battery.

[ September 06, 2002: Message edited by: 3.4 slow to go ]</p>

[AMinor65]

It could be your new alternator, but not likely. I bet that it's your battery. I know you had it charged, but sometimes they'll just hold a charge a short while when they're going bad. You have any power accessories that could've been left on. I've also heard of shorts in the electrical system draining power also.

[rockotman]

My bet is on the battery also - just because it takes a charge, it doesn't mean it will hold it.

[Teele]

Yeah, but if it was the battery, wouldn't the car be able to run off of the alternator???

[rockotman]

Good point - but if the battery was fully charged only last night, you should have been able to go for a day or two (assuming you didn't use lights, wipers, and such) on just the charge in the battery, even if the alternator wasn't putting out. Now if there is a short somewhere in the electrical system, it could keep the voltage low and drain the system as you describe.

Also, a battery that will not hold a charge can cause an alternator to fail prematurely.

Can you jump start the car now? If it takes more that a few minutes of charging when trying to jump it, the battery is probably shot, and if the voltage doesn't come back up to at least 13.6 withthe engine running, the alternator is probably gone again too. Is there any whining coming from the alternator?

As someone else pointed out above, also check for something that may be draining the battery rapidly, like a short or low insulation resistance in one of the battery cables.

[ September 07, 2002: Message edited by: rockotman ]</p>

[gregmondro]

check the diodes on the alternator. You can take off the alternator and then open it up (that black part). There are like these three little 'windows' in there that should all be the same color (blue or green if I remember correct). If one is black, then that's your problem.

My alternator went out and I did this and sure enough, the alternator was dead (got it replaced under the GM Certified Vehicles Warranty).

[Teele]

Well, I took back the alternator and got a new one and I'm not sure how it is yet. I'll will let you know.

Teele

[lord_gufi]

this happend to me this summer also i think its a conspiracy cause it also happend to 3 of my friends my brother and dads batts, i changed my alt and battery and after puting in the alt i though all was fine but it charged funny, well i took the batt off my old broken down ta and car has been running Peachy ever scince nothing has been at all a problem

[Skullcamaro]

If it is your battery, your alternator will not sustain all the needs of your car. Starting your car puts a tremendous amount of strain/power needed to start it and keep it going. The alternator just replenshes the power and keeps the voltage/current at a semi steady rate. Most likely it is the battery, it is most likely just defective or worn out and won't hold a charge for a period of time or is malfunctioning by releasing all the stored energy and not allowing it to be replaced. I say that you should have the battery checked and replaced. Its a difficult problem to lock down, but most likely it is your battery.

[Teele]

I took back the alternator, and they tested it and they said it had a short in it. They took another one off the shelf, tested it, and they said it was bad too. They tested another one, and it was good, and they gave me that one. I'm glad it was the alternator and not something else shorting out somewhere. Thanx a lot! Teele.

[cb1101]

is it true that a brand new battery will sometimes screw up your alternator?

this kid that went to lincoln tech. told me this when i changed my battery, and about 3 weeks later...my alternator was crapping out on me.

just a coincidence?