Q: My car stalls at idle; the battery is good, so is it the alternator?

asked by on

Last Monday my car turned off when idle at the light. The dashboard lights and radio started fading out. It wasn't until I got home when the car would start again but when idle it turned off again. Now when I try to start the car all the lights come on the car but the engine makes a noise like it trying to crank but will not

My car has 227000 miles.
My car has an automatic transmission.

This sounds like a potential problem with the charging system. The primary function of the battery is to start the vehicle. Once it is running, the alternator provides all electrical power for the vehicle. However, the battery does function as a sort of back up to the alternator. If the alternator has failed, either internally or due to the voltage regulator, the electrical system will then draw power from the battery. Since the battery does not produce power once it is drained, once the energy that it does have in reserve is depleted, there is no more electrical power to run the vehicle. There may be just enough power for things like the lights and radio to come on, but not enough to power the vehicle’s electrical needs completely. I would recommend having a certified technician, such as one from YourMechanic, inspect your vehicle to diagnose the exact cause of your stalling problem.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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!
  1. Home
  2. Questions
  3. My car stalls at idle; the battery is good, so is it the alternator?

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: My car shut off while driving and it tries to crank but can't for some reason.

Hello. A no start condition can be caused by many things. If a component touched the tailpipe and burned then it may very well be possible that it is related to your problem. I would recommend trying to identify what...

Q: Q: RPMs going up and down

This is most likely caused by a faulty Idle Air Control valve (IAC valve). This valve regulates the speed of the engine's idle by creating a controlled vacuum leak in the intake manifold. It is also possible that there may...

Q: The roof courtesy light, ( not the front) went out together with the bluetooth and back parking sensor.

Hi there. Sounds like a ground wire or open to short wire in the circuitry in your lighting system. Check all of the wires under the vehicle and see if any of them have burn or bare metal markings. If...

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...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.