At service stations, the generator's operation is tested on a stand. In garage conditions, its operation can be roughly estimated by the light intensity of the headlights.
If you discover a malfunction of any electrical device in your vehicle during operation, contact a specialist immediately.
Start and warm up the engine. Turn on the low beam headlights and note how bright they are. Increase the crankshaft speed to 2000–3000 min⁻¹ (if there is no tachometer in the instrument cluster, press the accelerator pedal until the economy meter needle reaches the yellow zone). If the headlights become brighter, the generator is working properly. Do not turn on other power consumers during the test.