Note. Before starting work, read the precautions described in paragraph «Safety first!» and in paragraph 1 this chapter.
1. If the generator control lamp does not light up when the ignition is turned on, first check for contact in the electrical connections of the generator. If everything is in order, check if the lamp has burned out and the lamp socket is securely attached to the instrument panel. If the lamp still does not light up, check the continuity of the test lamp supply wire from the alternator to the lamp socket. If everything is normal, then the generator is faulty. It should be replaced or taken to an automotive electrician for inspection and repair.
2. If the generator warning light is on while the engine is running, stop the engine and check the condition and correct tension of the drive belt (see chapter 1A or 1B), as well as the reliability of the electrical connections of the generator. If everything is normal here, check the generator, and you should contact a car electrician for verification and repair.
3. If alternator malfunction is suspected, despite the fact that the test lamp is working correctly, you can check the regulated voltage by proceeding as follows.
4. Connect a voltmeter to the battery terminals and start the engine.
5. Increase the crankshaft speed so that the voltmeter shows a stable voltage. The reading should correspond to approximately 12-13 V, but not exceed 14 V.
6. Turn on the maximum number of electrical consumers (e.g. headlights, heated rear window and heater fan) and check if the alternator supports a regulated voltage in the range of 13-14V.
7. If the regulated voltage is not correct, the fault may be due to worn brushes, weakened brush springs, failure of the voltage regulator, diode failure, open winding, or worn or damaged alternator slip rings. The alternator should be replaced or taken to an automotive electrician for inspection and repair.