Testing alternator by removing battery cable can you test an alternator by removing battery cable.
Battery cable alternator test.
Pcm tcm electronic power steering radio etc.
When the smoke clears that simple test could end up costing you several thousand dollars for new electronics.
The second you disconnect the battery the voltage regulator pegs the alternator to put out maximum power.
Again you should see a reading of 0 3 volts or less to be.
Testing alternator by removing battery cable was a valid test back in the day before computers.
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.
Start vehicle and voltage on voltmeter should increase to around 13 volts and stabilize there.
To do a quick check on an alternator i was told that you could start the car and then remove the negative battery cable.
That was the risk of it.
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.
Test alternator by connecting voltmeter on dc 20 red on positive battery terminal and black on 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.