Alternator Repair

A whining noise from the alternator can stem from various issues. Common causes include worn-out bearings within the alternator, which lead to friction and noise over time. Incorrect tension in the alternator belt, whether too tight or too loose, can strain the alternator and produce a whining sound.

The alternator may not be charging the battery due to various factors, including a faulty alternator, issues with the alternator belt such as looseness or damage, a malfunctioning voltage regulator, poor electrical connections between the alternator and the battery, a degraded or damaged battery, problems with fuses or wiring in the charging system, or excessive power consumption from accessories.

Driving a car with a bad alternator is not recommended as it can lead to various issues and potential dangers. While the car may run for a short period solely on battery power, once the battery drains, the vehicle will stall, leaving you stranded. Additionally, driving with a failing alternator can cause electrical systems to malfunction, affecting critical components like the ignition system and fuel injection.

To determine whether the issue lies with the battery or the alternator, you can conduct a few diagnostic tests. Start by checking the battery's condition using a multimeter to measure its voltage. If the battery voltage is below 12.6 volts when the engine is off, it may be discharged or faulty. Next, start the engine and measure the voltage again; it should read around 13.5 to 14.5 volts, indicating the alternator is charging properly. If the voltage remains low or doesn't increase while the engine is running, it suggests a problem with the alternator. Additionally, a battery warning light on the dashboard or dimming headlights while driving can also indicate alternator issues.