alternator problems

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how do i tell if the alternator is working

nasty90 in Chino Hills CA

·

Nov 13, 2010

·

3 Replies

Popular Answer
user91328on Nov 13, 2010

put a voltmeter on the battery with the motor running. it should be between 13.7 and 14.5 volts. any lower and you may have a failure. Roy

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wrenchedon Nov 13, 2010

On most cars all you have to do is unhook the positive side of the battery when the car is running. If it dies the alternator is not working. If it is not working your battery will just run out of juice, no light, no start.

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Machinehead6on Nov 13, 2010

Check the voltage at the battery, you can do it with the lights on to see if it holds under load. DO NOT REMOVE THE CABLES WHILE THE ENGINE IS RUNNING! This worked on older cars but ones with computers are sensitive to voltage spikes wich you will get if you remove a cable while its running. Steve

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