Q: Q: Alternator or Battery?

asked by on

Driving home, my windshield wipers seemed sluggish, everything else seemed normal. As I turned into my driveway, my radio and nav system shut off, I got a battery light on my dash. I rev'ed the engine and the battery light went off, the radio and nav turned back on. Moments after I let off the gas my instrument panel flickered and again with the battery light. I was able to again rev my engine and get things to normal again.. only for a moment once I let off the gas same type scenario. I pulled forward into my parking sspot, no power steering at this point. I shut the car off can could not start it again. Does this describe alternator failed, dead battery or something else?

My car has 85000 miles.
My car has an automatic transmission.

Greetings! This definitely sounds like you may have an alternator beginning to fail. As you know, the alternator is responsible for charging the battery. The rate at which this happens is correlated to the engine RPM’s as the alternator turns with the rest of the various engine pulleys. This is why the battery light tends to go away and the accessories all work properly as you rev the engine up. As you let off the gas pedal and engine RPM’s decrease again, the alternator charging rate also slows down. This may also potentially be connected to the voltage regulator failing as well. This is a unit that regulates the rate at which the alternator charges the battery. When this is not working properly, this may result in the alternator either over charging or under charging the battery and not maintaining the proper system voltage. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your charging system.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Q: Alternator or Battery?

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: Why won't my truck charge the battery?

Hi there. Several situations could prevent adequate charging from an otherwise healthy electrical system. These include poor connections at the batter posts, power cables at the alternator, ineffective grounding between the battery, chassis, and engine (good connections and large enough...

Q: My electronic steering power steering light came on my 2006 lexus gs300 and i cant turn my steering wheel

The problem you are describing is electrical in nature. When this new type of "electronic" steering system first saw widespread use, there were occasionally problems due to design glitches and unforeseen operating issues. In 2009, there was a Lexus Service...

Q: My wheel is almost impossible to turn and I can not drive the car because of it .

You should check the power steering fluid to see if the fluid leaked out from a leak. If fluid is low then refill reservoir and start and turn wheel back and forth slow to see if steering gets better and...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
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.