Battery Cable Alternator Test

That was the risk of it.

Battery cable alternator test.

Start vehicle and voltage on voltmeter should increase to around 13 volts and stabilize there. Pcm tcm electronic power steering radio etc. Testing alternator by removing battery cable was a valid test back in the day before computers. The second you disconnect the battery the voltage regulator pegs the alternator to put out maximum power.

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. But it s also possible that the alternator is actually in a bad shape but is producing enough to run the. Now about the ineffectiveness of it the vehicle will run if the alternator is producing enough juice. Technically yes but that test can also wind up destroying all the electronics in your car.

So when you test an alternator by pulling battery cable you increase the probability of killing that regulator. Dear tom and ray. With no battery in the circuit to act as a buffer the alternator can put out up to 150 volts depending on engine rpm. Again you should see a reading of 0 3 volts or less to be.

Doing this would allow you to check whether the alternator is putting out enough current to run the vehicle. Test alternator by connecting voltmeter on dc 20 red on positive battery terminal and black on negative battery terminal.