The control lamp does not light when the ignition is turned on. Control devices do not work
| Possible malfunctions | Method of elimination |
| 1. The fuse in the mounting block has blown. | 1. Replace the fuse. |
| 2. Open circuit in the instrument cluster power supply circuit: | 2. Do the following: |
| - no voltage is supplied from the mounting block to the instrument cluster; | - check the "0" wire and its connections from the mounting block to the instrument cluster; |
| - no voltage is supplied from the ignition switch to the mounting block. | - check the wires "G", "GC" and their connections from the ignition switch to the mounting block. |
| 3. The ignition switch does not work, | 3. Check and replace the faulty ignition switch contact part. |
The control lamp does not light when the ignition is turned on and does not light when the engine is running. Control devices work. The battery is discharged
| Possible malfunctions | Method of elimination |
| 1. The control lamp has burned out or the contacts of the lamp holder are not pressed tightly enough to the printed circuit board. | 1. Replace the burnt-out indicator lamp, bend the contacts of the lamp holder or replace it. |
| 2. Open circuit between the instrument cluster and the generator "D" plug. | 2. Check the "KB" wire and its connections from the generator to the instrument cluster. |
| 3. Wear or sticking of brushes, oxidation of contact rings. | 3. Replace the brush holder with brushes, wipe the rings with a napkin soaked in gasoline. |
| 4. The voltage regulator is damaged (open circuit between the "DF" terminal and "ground"). | 4. Replace the voltage regulator. |
| 5. The wire has become disconnected from the "D+" terminal of the brush holder. | 5. Connect the wire. |
| 6. Short circuit in positive valves. | 6. Replace the rectifier unit. |
| 7. Unsoldering the excitation winding leads from the slip rings. | 7. Solder the terminals or replace the generator rotor. |
The indicator light is bright or dim when the engine is running. The battery is discharged
| Possible malfunctions | Method of elimination |
| 1. Slipping of the generator drive belt. | 1. Adjust the belt tension. |
| 2. The voltage regulator is damaged. | 2. Replace the voltage regulator. |
| 3. The rectifier block valves are damaged. | 3. Replace the rectifier unit. |
| 4. The excitation winding power supply diodes are damaged. | 4. Replace the diodes or rectifier block. |
| 5. Unsoldering the excitation winding leads from the slip rings. | 5. Solder the terminals or replace the generator rotor. |
| 6. Open or short circuit in the stator winding, short circuit to ground. | 6. Replace the generator stator. |
The control lamp lights up when the engine is running. The battery is being recharged
| Possible malfunctions | Method of elimination |
| 1. The voltage regulator is damaged (short circuit between the "DF" terminal and "ground"). | 1. Replace the voltage regulator. |
Increased generator noise
| Possible malfunctions | Method of elimination |
| 1. The generator bearings are damaged. | 1. Replace the rear bearing or front cover with bearing. |
| 2. Interturn short circuit or short circuit to ground of the stator winding (generator "howl"). | 2. Replace the stator. |
| 3. Short circuit in one of the generator valves. | 3. Replace the rectifier unit. |