Battery Cable Alternator Test

But it s also possible that the alternator is actually in a bad shape but is producing enough to run the.

Battery cable alternator test.

Pcm tcm electronic power steering radio etc. So when you test an alternator by pulling battery cable you increase the probability of killing that regulator. Test the negative battery cable by using the same procedure as above for the positive cable but this time you will have the red lead of the multimeter touching the metal housing of the starter motor and the black lead of the multimeter connected to the negative battery terminal. Doing this would allow you to check whether the alternator is putting out enough current to run the vehicle.

Dear tom and ray. Testing alternator by removing battery cable was a valid test back in the day before computers. Now about the ineffectiveness of it the vehicle will run if the alternator is producing enough juice. Test alternator by connecting voltmeter on dc 20 red on positive battery terminal and black on negative battery terminal.

To do a quick check on an alternator i was told that you could start the car and then remove the negative battery cable. Technically yes but that test can also wind up destroying all the electronics in your car. With no battery in the circuit to act as a buffer the alternator can put out up to 150 volts depending on engine rpm. That was the risk of it.

Start vehicle and voltage on voltmeter should increase to around 13 volts and stabilize there. Again you should see a reading of 0 3 volts or less to be.