my battery light comes on i can rev the motor and it will go out?

2004 GMC CANYON

239,000 MILES

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1 POST

my battery light comes on i can rev the motor and it will go out . i checked voltage at battery when light is on 11.9 volts rev engine light goes out and stays out with 14 volts what is my problem

Jan 14, 2013 at 5:56 AM

KASEKENNY

✓Experienced Mechanic
18,907 POSTS

More than likely you have an alternator that is failing. This means we need to test the alternator and it sounds like you already have but here are a couple guides that will help with this:

https://youtu.be/Z-p4dMJUpUw

https://www.2carpros.com/articles/how-to-check-a-car-alternator

https://www.2carpros.com/articles/how-to-replace-an-alternator

I am attaching the process below on how to replace the alternator as I suspect this is the issue.

Please run through this and let me know what you find. Thanks

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Professional Diagram for 2CarPros Members
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Dec 28, 2021 at 9:00 AM