battery or bad rebuilt altenator - Automotive Wiring and Electrical


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battery or bad rebuilt altenator

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Auto Repair Home>> Automotive Repair>> Automotive Wiring and Electrical

kchofmann
New User

Oct 3, 2007, 10:57 AM

Post #1 of 3 (1562 views)

battery or bad rebuilt altenator	Sign In

I have a 99 alero and it is driving me crazy. The car's battery light came on and had a feeling the altenator was going. A day later the car was driving and the car stalled. Once we jumped the car the caharge would only last a short while and we would stop and recharge. My friend told me that the altenator was bad. So I went and bought a rebuilt altinator put it in and the car started right away. Took the car home with no battery light and thought everyhting was fine. The next day the car was driven by my fiance and she got to work and noticed the battery light was comming back on. SHe got in the car after work the car was dead. She got the car jumped and took the car to autozone where less than a year ago we got a brand new battery and asked to have the battery charged to see if the battery was charged fully. THe battery was charged and by the time she came back home the battery light was on again. I am either thinking I got a bad rebuitl altenator or have a bad cell in the battery. Any help with my problem would be great thanks!!.

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Oct 3, 2007, 11:54 AM

Post #2 of 3 (1558 views)

Re: battery or bad rebuilt altenator	Sign In

Note: A fully charged battery in good shape may only get you an hour or less or drive time without help from the alternator. Not sure what triggers the "Bat" warning light. I know that some problems won't set it off. Despite a battery test it can still have a failure. Did AutoZone or you charge the battery prior to testing? If not the test is a waste of time.

Just put a voltmeter on your battery. Engine off should be real close to 12v - more if it was just running. Now with it running check the volts which should be over 13.5 and under 14.5 all the time the engine is running even with most assories on. Bet it can't do that and the problem is either the alternator or perhaps just the regulator in it which comes with a replacement. Most folks don't take them apart for just the regulator or know how to test that, that is the only problem.

When a battery gets way too low on charge for any reason it's hard on it. Only certain special batteries can take that too much without damage. Other problem is when a battery is low too often and the alt works it works way too hard to restore a full charge (or working to charge a failed battery) and it will burn out the alternator. They get hot and can't take that for long. If you must jump start a car it's best to leave donor car hooked up for quite a while to get the dead battery up to a moderate charge. This will be hard on both cars so it should be AYOR and the donor car should be willing to take a risk. It's always best to charge a battery from a battery charger and to do it slowly - either trickle charge or just the 15amp charge if you can't wait 12 or more hours.

You can get a cheap multi meter for about $10 bucks if you don't have one. They are handy as all get out for lots of things so it should be in you tool box or collection of tools,

T

DrElectrics
Enthusiast

Oct 3, 2007, 3:23 PM

Post #3 of 3 (1552 views)

Re: battery or bad rebuilt altenator	Sign In

^ What he said ^ Although, you may have gotten a shoddy ALT. But Tom is right. If the battery is too far gone, the ALT cant charge it properly.

*SOLUTION*
If what Tom suggested dont work, at least you will have readings on your battery and ALT. Buy a Gel Cell Battery. No maintenance required and they are hard to kill. Then, buy a NEW ALT. The warranty is better and you know it hasnt been bashed together like in a reco. But thats only if Tom's suggestion doesnt work.

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