Alternator voltage test

Connect a voltmeter to the battery terminals.

Start the engine. When starting, the voltage should not fall below 8 V (at +20°C).

Increase the number of revolutions to 2000 rpm. The voltage should be between 13.6 and 15.2 V. This is proof that the alternator and voltage regulator are working. Generator voltage (board voltage) must be higher than the battery voltage to ensure that the battery is charged while driving.

Check voltage stabilization. To do this, turn on the main beam headlights and repeat the measurement at 2000 rpm. The measured voltage should not differ from the previously measured voltage by more than 0.4 V.

If the measured voltages are out of tolerance, have the generator checked by a workshop.