American Cars
Alternators
Car Batteries
Ford Aspire

How do you tell if your alternator is bad?

Answer

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Wiki User
06/14/2015

If the voltage metere is moving up and down there a good chance that its the alt. You can also place a volt meter on the battery while the motor is running (with every thing off), look and the voltage, then turn your A/C on high, turn your lights, wipers, radio ON, if the voltage goes below 12.5, there a good chance that it is bad.