Skip the auto shop - Our mechanics make house calls

Q: Loud humming noise

asked by on

The battery light icon and check charging system came up, and it's making a loud humming noise. I believe the alternator needs replacing.

The bearing or brushes in your alternator are likely going out. You could also have another issue in your belt drive system causing the noise and lack of charging.

A visual inspection of the drive system, a stethoscope to listen for noise, and a multimeter to test your battery can determine the cause of your car’s issues. I recommend having a certified mechanic, such as one from YourMechanic, diagnose your car’s humming noise and Battery Light to recommend the best path to repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Tcs light and check engine light

Hello, thank you for writing in. When check engine lights illuminate, the first step to take is to have it scanned for diagnostic codes. These are the codes that trigger when a sensor or computer detects any issues. This can...

Q: Why does my rpm rev up but the car doesn't accelerate

Hello there, many faults will cause your RPMs to increase but the car not to accelerate. This is called a slipping clutch and happens when power is applied when in gear. There are several causes for a slipping clutch; the...

Q: Why do I need to charge my car's battery ever week or two but I cannot find an obvious problem withe the electronic system.

If you are starting the car and only operating it for a very short period, such short duration operation does not give the car's charging system sufficient time to re-charge the battery. Consequently, repeated short trips, especially in cold weather...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...