Alternator not charging?

BLENDY1303

MEMBER
2015 HONDA ACCORD
2.4L
4 CYL
4WD
AUTOMATIC
59,000 MILES

I have the car listed Sport model. My question is that I’m trying to figure out if I have an alternator problem. I use my multi-meter to test the battery and the alternator. The battery starts at 12.7 when the car off when I turn the car on with no load it goes up to 13.4 then back down to 12.5. Now when I turn on the AC and the headlights it jumps up to 14.4. I search online and it say that when I turn the car on it should stay between 13 - 15v with no loads. I feel like I’m losing power in my car I also see my headlights dimming when I have the ac on or when I’m turning the steering wheel left to right.

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

Hi,

This could be an alternator that is beginning to fail. However, I do not think it is cause for alarm as of now.

Here is a guide on how to test the alternator. You can also take it to a local shop that tests them and have the alternator load tested.

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

Keep in mind, vehicles that are relatively modern which yours is, will do what is called duty cycle the alternator. This means it will raise and lower the voltage based on the need. The spec that you found for no load is accurate but your are not that far outside the spec so I would not replace the alternator based on just this reason.

I would feel ok because your alternator has gone up to 14.5 volts under load which is what it is supposed to do.

As for the flickering when the loads kick on and off, this is normal. I would not worry to much about it because if you think about the lights in your house when the AC is on and the dishwasher or something else kicks on, the lights dim for a second. This is typical of electrical systems.

The alternator is there to supply the power needed so if this gets worse then it may be faulty but again, I would not worry to much based on what you gave me to this point.

Let me know if you have other questions. Thanks