my battery light came on in my crx HF which is bone stock, it came on last night while i was driving but the battery is brand new, i thought it could be the alternator also but the car starts up everytime and doesnt lose power i check the battery with a multi meter and it starts at 12.10 then goes down to 12.9 and so on very very slowly but when i restart the car its back at 12.10

battery or alternator?

 

Starting at 12.1 and then going down to 12.9 doesn't make much sense grammatically... First off, the battery should be at LEAST 12.5 pretty much no matter what. Being a new battery makes me suspect the alternator or grounds ESPECIALLY if the battery light is on when the car is running. The only time the battery light comes on is if you lose charging almost entirely.

1. Make sure your alternator wire is connected,
2. Make sure the terminals are clean and check the 3 major grounds.
3. Make sure your belt is on and adjusted correctly
4. If that all fails have Autozone test the alternator and replace if bad.

Do all of that and get back to us with the results, I am curious.

 

Best post iv seen from a new member in a while

 

?

 

Follow that. /thread. your voltage with the engine running should be mid 13s.

 

should be 14.5V while running.

not 12.5, not 13.

its not a battery light, its a charge warning light and it almost always means you need a new alternator. "new" ones from autozone and parts stores fail very often, and soon, if not right out of the box. so get used to replacing them.

 

Holy crap, I was way off. Thanks for the correction. That means I have to go back and take a better look at my friend's scion. oops.

 

For less than the price of an autozone alternator I actually bought a Hi-output one off of ebay. You can buy any 88-95 Civic d-series alternator, they're all the same I believe. 92-95 put out 10 more amps.

(Not sure if it's actually Hi-output or not, I just needed an alternator.)

http://www.ebay.com/itm/ws/eBayISAPI...m=130645690631

At the same time I did the big 3 upgrade and it took care of all of my electrical problems including a lingering charging light problem and lights dimming at idle. The new alternator and grounds also made my A/C suck less power; my car didn't bog as bad coming from a stop. My car now turns over so fast you could probably drive it with the starter alone.

Cleaning/replacing the terminals made a big difference for me. If you can afford it, (like 20$ in cables) it's an awesome upgrade. If not, just clean em.

 

Or buy a mechman alternator.

 

well guys it turns out my battery is good and it was the alternator, the funny thing is that i never thought an alternator could slowly fail lol, i thought it would be all at once but its somehow still charging the battery, thx for the input everyone

 

So true Tyson. Between the "lifetime" alternators and starters I am a pro. Once I changed out the OEM parts for the "new" parts, they each seem to fail within a year. You'll be a pro in no time.

Should be no more than a two beer job