Pull Battery Cable To Test Alternator

If the engine cuts off it is a sure sign that the alternator has died.

Pull battery cable to test alternator.

Pcm tcm electronic power steering radio etc. Start vehicle and voltage on voltmeter should increase to around 13 volts and stabilize there. Today you risk frying every electrical device in your vehicle. Some newer cars will turn off even if the alternator is working good.

If you re tempted to test an alternator by disconnecting the negative battery cable don t do it. To do a quick check on an alternator i was told that you could start the car and then remove the negative battery cable. Community answer test alternator by connecting voltmeter on dc 20 red on positive battery terminal and black on negative battery terminal. A good alternator may indeed keep the engine running without the negative cable but this was never a good test.

Technically yes but that test can also wind up destroying all the electronics in your car. Doing this would allow you to check whether the alternator is putting out enough current to run the vehicle. What are your thoughts. Testing alternator by removing battery cable was a valid test back in the day before computers.

Connect it to the battery and it should read a little above 12 volts when its off and 13. Can you test an alternator by removing battery cable. If it decreases and starts to drop until vehicle eventually dies you have a defective alternator.