1. Connect a voltmeter to the battery terminals.
2. Start the engine. When starting, the battery voltage may drop to 8 volts at an air temperature of +20°C.
3. Increase the engine speed to 3000 rpm. The battery voltage should be 13.5-14.8 volts. This is evidence that the alternator and voltage regulator are functioning properly. Generator voltage (onboard voltage) must be higher than the battery voltage so that the battery is recharged while driving.
4. Check the stability of the voltage regulator. Turn on the high beam, the interior blower and repeat the voltage measurement at an engine speed of 3000 rpm. The voltage should be 13.5-14.8 volts. If the data obtained does not match the nominal, then check the generator in the workshop.