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Can a defective alternator cause a battery read of 11.8 while the engine is running?
Wiki User
∙ 12y ago
Yes. You should read from 13.5 to 15.5 volts at the battery with the engine running. Your alternator is not putting out any voltage. Remove it and have it tested at your local auto parts store.
Wiki User
∙ 12y ago
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Why new battery and alternator won't hold a charge when car is running?
The alternator does not hold a charge. It charges the battery. If it will not charge the battery then either the alternator is defective, battery is defective, or the connections are corroded or loose. You should read 13.5 to 15.5 volts at the battery with the engine idling. Check it with a DC volt meter. If you get less the alternator is defective. If you get much more the voltage regulator is defective.
Will the alternator run the battery low?
If the alternator is not charging the battery, then it will eventually go dead If the voltage regulator (in the alternator) is defective it will eventually kill the battery Check the alternator with a voltmeter A fully charged battery (without engine running) should read approx. 12.8 volts With engine running should read 13.8-14.2 volts
Why wont your brand new alternator recharge your battery?
Maybe the battery is defective. Check the voltage at the battery terminals with the engine running at idle. You should get 13.5 to 16 volts. If not the alternator is defective or the voltage regulator is bad. If you are getting the correct voltage, the battery is bad or the connections are corroded.
Why battery voltage reading decrease when you accelerate the engine?
Alternator is defective.
Will your alternator recharge your battery if you let it sit for a while?
If the engine is running and the alternator is good. If the engine is not running, no.
How do you know if the alternator is not charging?
Check the voltage at the battery with the engine running. It should read from 13.5 volts to 16 volts. If it reads lower than 13.5 volts the alternator is defective.
Can a car battery be bad if its still pushing 12 volts?
Yes. A fully charge battery will read 12.6 volts with engine not running. A 75% charged battery will read 12.4 volts. At 50% charge, it will read 12.2 volts. At a 25% charge it will read 12 volts, but that will not be enough to even start the engine in most cases and unless the alternator is bad the battery is defective. With the engine running you should read 13.5 to 15.5 volts at the battery. Any less and the alternator is defective.
Why would a 12 volt car battery give off 22 volts?
it won't. The most you will see from a stationary battery with the engine not running is 12.6 volts. If you are seeing 22 volts with the engine running then the voltage regulator is defective and it will ruin the battery. Most modern alternators have the voltage regulator built into the alternator. Replace the alternator.
Why would a 2004 envoy battery drains while driving?
Alternator is defective or the battery has a dead cell and will not take a charge. Check the voltage at the battery with the engine running. You should have between 13.5-16 volts. Anything less and your alternator is bad.
Why is your 1988 Chevrolet truck with a 305 engine running of the battery only and not the alternator?
If it is running on the battery only then that means the alternator is not charging the battery.
How do you get the alternator to turn over?
The alternator is run by a belt connected to the engine. When the engine is running the alternator is turning. The alternator is what produces the electrical current that charges the battery & powers everything electrical while the engine is running. the battery is mainly to start the engine.
How high should charge on 12 volt car battery read?
The battery should read 12 volts with the engine off. With the engine running it should read 13.5-16 volts. Any less and the alternator is defective. Any more and the voltage regulator is defective.
