What Are the Common Faults of Automotive Generators?
2 Answers
Common faults of automotive generators include: 1. No charging; 2. Insufficient charging current; 3. Excessive charging current; 4. Unstable charging current and generator failure to generate electricity. The automotive generator serves as the primary power source for vehicles, supplying electricity to all electrical equipment except the starter when the engine is running normally, while also charging the battery. An automotive generator consists of components such as the rotor, stator, rectifier, front and rear end covers, fan, and pulley assembly. The working principle of an automotive generator is as follows: when an external circuit energizes the excitation winding through brushes, a magnetic field is generated, magnetizing the claw poles into N and S poles.
I've been driving my old car for years and have personally experienced alternator issues. The most common problem is abnormal output voltage. During long trips, the battery would often drain at night, with dashboard lights flickering constantly—this was actually caused by a faulty alternator overcharging and damaging the battery. Another issue was the squealing belt, especially noticeable during rainy days or cold starts, which turned out to be due to a loose or broken belt. There was also this rattling noise inside the car, indicating bearing wear—if left unrepaired, the alternator could seize up. Internal component failures like burnt-out diodes are also common, causing unstable current flow and flickering lights. It's best to get early diagnostics when the battery warning light comes on—don't delay repairs to avoid being stranded on the road.
