Preparing for the test
1. Before testing, check the following items:
- a) The battery installed in the vehicle must be fully charged;
- b) check the tension of the generator drive belt.
2. Turn the ignition key to the "OFF" position.
3. Disconnect the cable from the negative terminal of the battery.
4. Connect a digital voltmeter to the generator "S (L)" terminal and "ground". Connect the positive probe of the voltmeter to the generator "S (L)" terminal.
5. Disconnect the wire from the generator terminal "B".
6. Connect a 0-100A DC ammeter in series between terminal "B" and the wire disconnected from the generator. Make sure that the negative probe of the ammeter is connected to the wire disconnected from the generator.
7. Connect the tachometer and the wire to the negative terminal of the battery.
Examination
1. Check that the voltmeter scale is clearly visible to determine the voltage value. Turn on the ignition and make sure that the voltmeter shows the battery voltage.
If the voltmeter shows 0 V, the electrical circuit connecting the generator terminal "S (L)" and the positive terminal of the battery is not closed, or the fuse link has burned out.
2. Start the engine and turn off all electrical consumers.
3. Increase the engine speed to 2,500 rpm⁻¹ and when the current decreases to less than 10 A, read the voltage value on the voltmeter.
Check result
1. If the voltage corresponds to the required value, then the voltage regulator is in good condition and is working normally. If the voltage differs from the required value, then the voltage regulator or generator is faulty.
| Voltage regulator temperature,°C | Adjustable voltage, V | |
| Generator 75A | Generator 90A | |
| -20 | 14,2–15,4 | 14,3–15,2 |
| 13,9–14,9 | 14,1–14,7 | |
| 13,4–14,6 | 13,5–14,4 | |
| 13,1–14,5 | 13,3–14,3 | |
2. After completing the generator current limit test, idle the engine and turn off the ignition.
3. Disconnect the cable from the negative terminal of the battery.
4. Remove the tachometer, voltmeter and ammeter.
5. Connect the wire to the "B" terminal of the generator.
6. Connect the cable to the negative terminal of the battery.