Preparing for the test
1. Check the following items before testing:
- the battery installed in the car must be fully charged;
- Check alternator drive belt tension.
2. Turn the key in the ignition switch to position «OFF».
3. Disconnect a wire from the negative plug of the storage battery.
4. Connect a digital voltmeter between the terminals «S (L)» generator and «weight». Connect the positive probe of the voltmeter to the terminal «S (L)» generator.
5. Disconnect the wire from the terminal «B» generator.
6. Connect a DC ammeter with a range of 0-100 A in series between the terminal «B» and a wire disconnected from the generator. Make sure that the ammeter negative probe is connected to the wire disconnected from the generator.
7. Connect a tachometer and a wire to the negative plug of the storage battery.
Examination
1. Check that the voltmeter scale is clearly visible to determine the voltage value. The voltmeter should indicate battery voltage. If the voltmeter shows a voltage of 0 V, then the electrical circuit connecting the terminal is not closed «S (L)» alternator and positive battery terminal, or fuse blown.
2. Start the engine and turn off all electrical consumers.
3. Increase the engine speed to 2,500 min-1 and when the current drops to less than 10 A, read the voltage on the voltmeter.
Result of checking
1. If the voltage matches the required value, then the voltage regulator is good and working properly. If the voltage differs from the required one, then the voltage regulator or generator is faulty.
Voltage regulator temperature,°C | Adjustable voltage, V |
–20 | 14,3–15,2 |
20 | 14,1–14,7 |
60 | 13,5–14,4 |
80 | 13,3–14,3 |
2. After completing the alternator current limit test, run the engine to idle and turn off the ignition.
3. Disconnect a wire from the negative plug of the storage battery.
4. Remove the tachometer, voltmeter and ammeter.
5. Connect the wire to the terminal «B» generator.
6. Connect a wire to the negative plug of the storage battery.