Checking the generator voltage (VW Transporter T4)

1. Connect the voltmeter to the positive and negative terminals of the battery.

2. Start the engine. The voltage during starting should drop to 8 V (at an outside temperature of +20°C).

3. Increase engine speed to 3000 rpm. Voltage should be 13.5-14.5 V. This is proof that the generator and regulator are working. Generator voltage (on-board voltage) there must be more voltage in the battery so that the battery is charged during operation.

4. Check the stability of the regulator. To do this, turn on the high beam and repeat the measurement at 3000 rpm. The measured voltage should not exceed the previously measured voltage by more than 0.4 V.

5. If the measured values are outside the required value, check the generator at a service station.