Skip the auto shop - Our mechanics make house calls

Q: Battery light is on.

asked by on

So i bought a car from my sister and the battery light often comes on while its in park or just at a stop. The car will drop in rpms and almost stall or will stall. Battery light seems to disapear when actually driving though ao its pretty weird. My thought was maybe the alternator but my sister had that replaced quite recently. Any suggestions?

My car has 83000 miles.
My car has an automatic transmission.

Hi there. Either the drive belt to the alternator is slipping at low rpm’s or the alternator is not producing enough voltage and amperage at low rpm’s. Check the drive belt tensioner and see if it seems loose and not keeping the belt tight. If the belt is good and not slipping, then I recommend replacing the alternator. If you need further assistance with your battery light issue, then seek out a professional, such as one from Your Mechanic, to help you.

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: Front seat backs twisting when moving forward or back

These seats are reclined electronically via electric motor within the seat. This motor is only mounted on one side of the seat and acts directly on that side whereas the other side is acted on by a cable that is...

Q: Car idling high in park

At such a high idle speed, a large vacuum leak would be possible if the engine didn't return to a normal level after warming up. The idle air control valve regulates engine speed when the throttle plate is closed, allowing...

Q: altinater is fine but battery light keeps coming on what could be the problem? came on 7 times while on the road

The battery should be load tested by a professional. Load testing can only be reliably performed on a fully charged battery. If the battery passes a load test be sure it is NOT a marginal pass in which case you...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.