Why does my car battery warning light flicker on and off?
An intermittent battery light that changes with engine revs usually indicates a failing alternator or a loose drive belt failing to supply proper voltage at lower speeds. This prevents the charging system from maintaining a full battery charge while idling or driving under four thousand RPMs.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Using a battery maintainer overnight
- 2Taking longer drives of at least 60 minutes
- 3Replacing the alternator
- 4checking tire pressure and steering feel
- 5taking the car to a parts store to check codes
- 6inspecting battery terminals and health
- 7checking speed sensors for dirt
- 8Testing battery and alternator voltage
- 9Replacing alternator, spark plugs, timing belt, and battery
- 10disconnecting the battery to reset systems
- 11taking the car to a dealer for diagnostics
- 12Getting diagnostic tests done at auto parts stores like AutoZone
- 13Asking online forums for second opinions on alternator health
In their words
Unedited, most upvoted first, each linked to the thread it came from.
“It'll go weeks without the light coming on but every now and then it'll flicker like in the video. I've tested this battery and alternator and they're both reading good voltage.”source ↗
“My battery light comes in, usually a few seconds after I start driving the car, but will almost always turn off if im revving past 4k rpms, then back on once I drop under.”source ↗
“Hello, these lights are appearing on my dashboard. They don’t appear every time I turn on the car. I checked all my tires, they’re good. Steering feels fine etc. It drives exactly the same. How can I get rid of these?”source ↗
“Recently the computer system has been kind of freaking out and flashing all kinds of warnings. Car still feels and drives fine.”source ↗
“Car was fine for a week, but now it’s happening again.”source ↗
“No, it wasn’t. They seemed confident that would fix the issue. Feeling potentially scammed now.”source ↗
“Today I turned on my car and there was no battery signal for 2 minutes. Then the signal appeared for 2 minutes and went away when I arrived at auto zone (7 minute drive)”source ↗
“They tested the car with the battery signal off, and they said the charging system has no problems.”source ↗
Where this came up
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