Any noise coming from the car's alternator is abnormal and it is necessary to check and confirm the fault location to prevent the fault from spreading.
There are two causes of abnormal noise in automobile generators:
1. The noise is caused by the generator belt becoming loose. When the belt is loose, there will be relative movement. between the belt and the pulley. This type of movement will produce a special whistling sound, which mainly occurs when the vehicle has just started or when electrical devices with high load such as headlights are turned on. When business is busy, there will be a smell of burning rubber in the engine room. The inspection method is to spray a small amount of clean water on the generator pulley when there is abnormal noise when starting the vehicle. If the abnormal sound disappears, it is belt noise. The solution to this kind of babnormal noise is to tension the generator belt to the appropriate position to eliminate it.
2 The sound of loose bearings or lack of oil is a metallic rubbing noise or a continuous brushing noise. Loosen the belt and rotate the generator pulley alone to check for play or abnormal noise. If there is a problem with the generator, the generator must be replaced and repaired