Do it yourself
Frequently asked questions about cars and motorcycles
Car tutorial (Do it yourself) Motorcycle tutorial (Do it yourself) Frequently Asked Questions

Testing the Proper Functioning of the Alternator

Model: BMW Serie 5 E39 - Years: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
Part: Alternator

See other generations:
Video tutorial

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


Related tutorials

Replacing the Belt and Alternator on a BMW 5 Series
Replacing the Belt and Alternator on a BMW 5 Series
BMW Serie 5 (1995-2003 / E39) Is the alternator not charging anymore? Let's see how to remove the alternator from the engine compartment of a BMW 5 Series. Open the hood, disconne…
Installing the Car Alternator
Installing the Car Alternator
BMW Serie 5 (1995-2003 / E39) To remove the alternator, disconnect the negative terminal of the battery, remove the belt, and locate and disconnect each electrical connection, inc…
Alternator Replacement Instructions
BMW Serie 5 (1995-2003 / E39) To replace the alternator, first disconnect the battery. Then, remove the engine air filter box (AIR BOX) to access the alternator. Next, loosen the …

Other guides you may be interested in

How to Activate or Deactivate 4x4 Traction on a Toyota RAV4

Below are the steps to activate or deactivate the 4x4 traction on a Toyota RAV4, following the instructions provided. First, get in the vehicle and start the engine; then press the 4x4 traction button located on the left side of the steering wheel to deactivate it. With the 4x4 traction deactivated, the warning light will illuminate on the instrument panel; simply press the button again to activate the vehicle's four-wheel drive, allowing you to tackle off-road or rough terrain.

Watch the video!


by ScegliAuto

More videos