Rep Power: 0

Here's the deal...

A couple of weeks ago the battery light starts flickering a bit. We go on a trip for two weeks (leave the car at home), come back, and the light is still flickering. But now we can tell the battery is just dying. Lights are dimming, etc. We go shopping, come back out, and the car won't start. We get someone to boost us, then we drive over to a local store and buy a new battery. We install the battery and the car is now running just fine... but... the battery light is still flickering (although less once the car is actually moving).

It's a 2005 4-door Civic. We've had it since new. I was told the stock battery lasted more than 5 years, which is actually pretty good. But my question is regarding the alternator: does it sound to you as if it is going as well? Is that why the light would still be flickering? How long should the original alternator last?

Thanks for any advice!

 
Rep Power: 228

The alternator almost surely needs to be replaced.

 
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Would you expect that the original alternator should be replaced after 5 years?

 
Rep Power: 228

It can happen.

 
Rep Power: 812

my original was replaced 2 yrs after i bought the car brand new. next napa alternator has so far lasted 6 yrs and still going. its just luck i guess. but a battery light coming on means the charging system (usually alternator) is bad, it will not come on for a dead battery.

 
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Yeah, now I realize I probably didn't even need to replace the battery. That's what happens when you panic... but I'm not sure what else I could have done since everything was happening around 9pm at night! So I just ran in and got a battery.

So, I'm going to stop by an auto place in a few minutes and have them check the alternator. Then I'll replace it if needed.

 
Rep Power: 812

its good to replace the battery every 5 yrs at least even if it still works. only a matter of time and if the old one got drained, it wouldnt have worked as well anyway.

 
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Right.

I just had the alternator tested... it's charging about 1 Volt too low... so I'm guessing it's at the start of being on its way out.

 
Rep Power: 228

 
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Yeah... I'm going to try and replace it myself.

NAPA has one for $182 (3 yr warr), and $214 (lifetime warr). Does that sound reasonable? (I'm in Canada.)

 
Rep Power: 228

Shop around. Are those prices for a new alternator? I would think you can get a lower price for a rebuilt alternator that carries a lifetime warranty.

 
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Ok, I'll keep shopping.

Also, I noted above that the test showed the charge being 1 volt too low (approx). Is that enough to be confident that it's the alternator in your opinion? Is it possible there's a bad ground or anything like that?

 
Rep Power: 228

Yes, 1 volt low is very meaningful when it comes to alternator charging. Replace it.

 
Rep Power: 0

OK... update time.

I went and picked up an alternator for the cheapest price I could find ($140). Yes, it's a rebuild.

However, the last two times I've driven the car, the charge light has not come on at all! So, I go and pick up a meter since I'd like to have one anyway, and then I drive home. I test the battery with the car off, and I get 12V. I start the car, and I get 15+ Volts. The fan turns on, and it is still +14 Volts. So... I'm not sure what's going on. I guess I'll see what it does in the morning.

 
Rep Power: 228

Measure the voltage across the battery posts with the brights on and the A/C set to MAX.

 
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Ok, that gave me between 12.5 and 12.8 Volts. So, I'm guessing that sounds low? Still no charge light on the dash though.

 
Rep Power: 228

Yes, even under high electrical load, the alternator should be able to keep the system voltage near or above 14V. Replace the alternator.

 
Rep Power: 812

yeah thats a bit low, but are your connections good? check the battery terminals and also the ground wires. usually the battery light should stay solid if it is really broken, but its possible that its on its way out soon. also tighten the alternator power wire (on the alternator behind the rubber boot). it may be loose.

 
Rep Power: 228

(1) 12V - engine off
(2) ~15V - engine on, no load
(3) <13V - engine on, high load

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(2) indicates that the battery terminal and alternator connections are fine.
(3) indicates that the alternator output is inadequate.