- a) Inspect the drive belt to ensure that it is tight and undamaged. If damaged, replace it (refer to Chapter Routine maintenance).
- b) Make sure the generator mounting bolts are securely tightened.
- c) Check the generator wiring and all connectors. All contacts should be reliable and not oxidized.
- d) Check the relevant fuses located in the engine compartment (refer to Chapter On-board electrical equipment). If a burnt fuse is found, eliminate the cause of the fuse blowing and replace it (if the corresponding fuse blows, you will not be able to start the engine or turn on any of the devices).
- e) Start the engine and make sure that there are no extraneous sounds coming from the generator (a whistling or squealing noise may indicate faulty bearings or worn brushes).
- f) Make sure the battery is fully charged. If one of the cells is damaged, the battery may draw excess current.
- g) Disconnect the battery cable ends (negative at first). Inspect the battery terminals and cable ends. If traces of corrosion are found, clean them thoroughly (refer to the materials in Chapter Routine maintenance). Connect the wire ends to the terminals and tighten securely.
2. Connect the voltmeter between the positive and negative terminals of the battery.
3. Start the engine. The voltage when starting the engine may drop to 8 V (at an outside temperature of +20°C).
[Material based on data from the portal: MercedesMan]
4. Increase the engine speed to 3000 rpm. The voltage should be between 13 and 14.5 V. This indicates that the generator and voltage regulator are working properly. Generator voltage (on-board voltage) must be higher than the operating voltage so that the battery is recharged when the vehicle is moving.
5. Check the stability of the voltage regulator. To do this, turn on the high beam and repeat the measurement at 3000 rpm. The obtained voltage should not be higher than the previously obtained value by more than 0.4 V.
6. If the obtained value is outside the specified value, take the generator and regulator to a service station for repair.