- Check the condition and tension of the alternator drive belt, if necessary, replace it (see chapter Engine);
- Check up reliability of a tightening of bolts of fastening of the generator;
- Check the condition of the generator wiring and its terminal connections, if necessary, remove the oxidation products, tighten the fasteners;
- Check the condition of the relevant fuses located in the main mounting block (see chapter Onboard electrical equipment), - before replacing the blown fuse, eliminate the cause of the overload;
- Start the engine and make sure that the generator does not make any extraneous noise - a whistle or squeal may indicate wear on the bearings or brushes;
- Check the completeness of the battery charge level - remember that damage to one of the cans can lead to an increase in current consumption;
- Disconnect both wires from the battery (first negative) and carefully examine the condition of the pole terminals, - if signs of corrosion are found, carefully clean the terminals, preferably using special tools, make sure that the wire ends are securely fixed on the terminals.
1. Check the output voltage of the battery with the engine off, the measurement result should be about 12 V.
2. Without disconnecting the fan from the battery, start the engine and begin to raise its speed until the readings of the device stabilize (about 3000 rpm). The measurement result should not go beyond the range of 13.5 ÷ 14.6 V, - the generator must provide recharging of the battery while driving.
3. Turn on as many electrical consumers as possible (outdoor lighting devices, heater fan, heated rear window, etc.) and make sure that the voltmeter reading remains within the range of 13 ÷ 14 V, the voltage may temporarily drop, but should return to normal again (you may need to slightly increase the engine speed).
4. If the output voltage exceeds the upper limit of the allowable range, it is necessary to replace the voltage regulator.
5. Excessive undervoltage can be caused by wear on the alternator brushes, weakening of the brush springs, regulator failure, diode failure, winding breakage, and damage to the collector rings. The condition of the brushes and commutator rings can be checked visually - in the absence of obvious damage, the generator should be removed from the vehicle (see Section Charging system - general information and safety measures) for more detailed inspection and refurbishment/replacement.