How Do You Test An Alternator With A Multimeter. Your voltmeter should read 0 AC volts. Any amount of AC voltage indicates a bad diode - youll need to replace the alternator.
If you connect the meter leads to the battery terminals and the meter shows that its in the 138 to 153 volt ranges engine running lights and accessories off that means the alternator is working as it should be. This is the page that is tabbed. How To Test The Alternator With A Multimeter.
This means the alternator is operating correctly.
One way you can check for the integrity of the alternator is by evaluating this drive belt. Black to black and red to red. With the engine running touch the meter probes to the battery terminals. Put the multimeters black cable to the negative terminal and the red cable to the positive terminal.
