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Testing the Proper Functioning of the Alternator

Model: BMW Serie 5 E39 - Years 1995-2003
Part: Alternator

What we call the alternator is a three-phase alternating current generator that, along with the battery, constitutes the fundamental components of a car's electrical system, providing sufficient current for all mechanisms in the car that need to be powered. The video is a simple test to evaluate the proper functioning of the alternator located under the hood, recognizable because it is connected to the crankshaft via a visible belt. With the engine running, disable the battery operation by disconnecting one of the two cables connected to either the positive or negative terminal; it does not matter which, as this interrupts the current flow provided by the battery. If the alternator is functioning correctly, the car will remain running with all warning lights on and all electronic mechanisms operational.

Updated on 9 February 2026 by ScegliAuto

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