Alternator does not charge battery. Alternator light glows.

First of all, is alternator charging the battery. Battery voltage when engine is off, should be at least 12.6 or better at battery posts.less than 12.4 with engine off. Battery is going bad. When engine is running at battery should be at least 13.8 to 14.2 or more if alternator is charging. You can go to any auto parts store, and get the charging system checked for free Advanced auto, Auto-zone, ETC, Good-Day! if battery and alternator are good. Heres how to check for a current drain. Disconnect negative terminal from battery, Hook a test light to the negative cable. connect opposite end of test light to battery negative post . wait at least 5 minutes, with test light hooked up. if light is on. Then start pulling fuses in fuse box, when the light goes out. thats the problem circuit.

Check your wire connections make sure they are tight. But it sounds as though your alternater is bad and not charging your battery. A local parts house can test it for you.

Check the serpentine belt and make sure it's warp around the alternator pulley.

The routing diagram is on the radiator support or under the hood.

Is there any belt noise emitted for the alternator area?

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Most alternator can last up to 120,000 miles or ~10 years.

A good auto parts store will able to test the charging system and battery for FREE.

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Most battery can last up to 48 months.

An Interstate brand battery can last beyond 60+ months.

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A healthy charging system will generate 13.8V.

A healthy battery will hold charge at 12.8V or above.


Use a volt meter and test the voltage.

Please post the result on reply.

Most auto parts stores offer testing for free. A volt meter can also be used to check alternator output. Connect the meter leads to the battery. The voltage should be at least 12 volts. If it isn't, then find out why. Just because a battery is new does not mean it is fully charged. If the battery voltage is OK, then start the engine and observe the meter. It should now read approx. 13.5-14.5 volts. If it does, then the alternator is charging. If it isn't, then the alternator should be tested. While your at it, you might as well check your belt tensioner for proper operation.
1. leave the engine running and the meter connected.
2. Turn on your lights and other accessories. (heater, radio, high beams)
3. Observe the meter reading.
The voltage should remain between 13.5-14.5 volts. If it doesn't, then determine the cause and repair as needed. If it does, then the tensioner and belt are probably OK. I hope this information is helpful to you and thanks for using FixYa.

disconnect the battery with the car running if it dies then its the alternator. You can also dive it to an auto parts store and they will check the charging system for you, it a free service Tim

sounds like your alt. went out you can have it tested at auto zone for free

HI:
The battery light means your car is running off the battery. check out your alternator,your alternator belt, and yor battery connections. Most auto parts stores will check your alternator for free!

you have to check the alternator first if it is not charging then battery will keep dieing from being used.

When you say it check ok, can you please explain what you mean in more detail, because if your Alternator light comes on or is dim, your alternator is likely not producing enough amps to fully charge the battery. The battery may test good, but the alternator has to work too hard to keep it charged. Have a check run on the amperage output on your alternator to see if it produces the factory recommended amperage. You can get a tester or probably borrow one from Auto Zone auto parts if there is one near you. If not, you can buy an amp tested from your local auto parts store or you can take it to your local shop and they might test it for free.

I have seen poor connections at the alternator cause the charge light to come on if they all seem to be ok it could be a faulty alternator some auto parts stores will test them for free