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Start the engine, while the engine is running, remove either battery cable. It should stay running, if not, possible bad charging system. Or take it to auto zone. They check them for free
NEVER EVER disconnect a battery cable while the engine is running unless you like your computers fried.
Here's a link to the proper way to test:
http://free-auto-repair-advice.blogspot.com/2007/09/avoid-bogus-alternator-test.html
Saying again, never ever disconnect a battery or alternator with the engine running. The resultant voltage spikes can fry electronics, the alternator diodes can be overloaded and fried...bad things can happen. The don't ALWAYS happen, but why risk $1,000's of dollars in damage when there are correct ways to test your alternator.
One simple way is at night star your car, turn off all electrical accessories, turn on your high beam head lights and point your car at a wall where you can see the reflected light well. Notice how bright they are. Turn off the car. If the lights get brighter, odds are very good your alternator is bad/weak.
Wiki User
∙ 7y ago
Wiki User
∙ 13y agoStart the engine and connect a volt meter to the battery posts. You should get a reading on the 20 volt DC scale of 13.5-16 volts. Any more or less and the alternator is defective.
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Dodge avenger battery dead?
Charge it, replace it,test the alternator,Charge it, replace it,test the alternator,
How do test your alternator while in the car and the car will not start?
Car would either have to be running or alternator removed for bench test
How do you wire alternator to a battery to test alternator?
run it and then disconnect the negative wire from the battery if alternator dies its bad.
How do i test a 24 volt alternator?
with a voltmeter
How do you test alternator in 2002 S10 pickup?
Either drive to your local auto parts store and have them test it in the vehicle or you can remove the alternator and take it to your local auto parts store and they can bench test it for you.
What is full-fielding?
Full fielding is a diagnostic test of the alternator You make the alternator work full out and measure the voltage and amperage output to test it against a published specification.
What can cause a battery light to come on when the battery and alternator both test good on a 1992 SC 400?
Battery light usually means alternator not charging. Most common solutions would be be a bad alternator, bad connection, or loose alternator belt. If the battery and alt test ok than check the connections to the alternator and battery.
How do you know when to replace the alternator when not running?
The alternator must be running to test without disassembly. If you remove it, many auto part stores will test at no charge. One test is a voltage test. Start the engine and use a multimeter to check the voltage at the battery. It should read between 13.5 and 16 volts. Any less or more and the alternator is bad.
How you can test a alternator?
Ask your local auto parts store to do it.
2004 Honda Element stalls?
it could be your crank posistion senson or alternator failing get a dia and a load test on alternator
How do you test an alternator on a 1996 Saturn SL2?
TAkeit to the Auto Zone store and they will check it free.
How do you know if your alternator is bad?
If it is makeing a noise or is not putting out at least 13.5 volts it is bad. Take the car or the alternator to an Auto Parts store and have them load test the alternator to be sure.
