Hi bros and sis.
I'm having a problem with voltage.
Ok morning is 12.0v-12.4v
On start engine is 13.8-14.2v
Everything is normal. But sometimes quite often whenever I'm driving on low rev the voltage will be on 12.6v. When I rev to 3k rpm+++ stable 14+v all the way. Speed on 85km/h stable at 14+v. At night time when i on my headlights the charging is normal. Whenever i on my air-con when driving also not much problem, but sometimes it will drop. When Idling no issue. Checked grounding no problem. Checked fan belt no crack, tension ok. Went to check with alternator repair man, had said should be voltage regulator. Not carbon brush dirty. Is there anyone got this problem with ge6 b4? Hope to get some advice.

 

If your resting battery voltage (24 hours after running the car) is less than 12.6 volts, your battery might be getting tired.

It's normal for the voltage to vary a bit between low and high RPMs. Why do you think this is a problem?

 

Thanks dude for the reply. Ok I'm on a high way with no aircon no headlights no radio. I travel on like a 10km non stop. With a below 3k rpm, speed maintain 80km/hr. the voltage will be 12+v all the way. I changed my batt bosch 5 mths ago.

 

It might be designed that way, you would have to look at the service manual real close. Its possible to save fuel and drag on the engine they turn the alternator off basically once the battery is charged from the drain caused by starting. I know the old CRX Hf's would do something similar, until you added a load they would stay around 12v then if you tapped the high beams it would jump back to 14v real quick.

 

pretty sure normal. the only time you get high readings is when the car is on and alternator running.

if you're worried get a cca reading. should be over 300.

 

Fits have an ELD just like other honda's its job is to regulate the alternator via the ECU to only be on "high power mode" 14.2+V when needed to save gas. So your description sounds normal, might not hurt to have the battery load tested just in case though.

 

Wow guys really thanks on the advice! Thanks!

 

Brothers n Sisters~
One windy day, i tried 70km/h on around 5km road distance. the voltage was 12++v.
I got some sound system on my fit 08. So i decided to blast abit to see if the voltage charge to 14v. Not really sure abt how ELD works. but when was halfway through my whole car kinda vibrate........ i faster on my air con and its normal again. Can anyone tell me where the ELD locate at?

 

It is located on the back side of the fuse panel under your dash, I would not recommend trying to bypass it. I have over 20 years in automotive audio experience and even I said "screw that" because it is just not worth the hassle. Depending on your wattage ratings of your amp(s) you should be fine, me I am running almost 3,000watts total so I have gone to adding a better battery under the hood, 2 more batteries in the back and I have a 200Amp High Output Alternator on the way.

In your case an upgraded battery and possibly doing a BIG 3 upgrade could help if you think your car is hurting a little from the audio drain.

 

thanks bro for the advice. Hmmm... but i feel there's something related on the charging.... traveling in a 70km/l on a 5-10km distance all the way it's stay 12+v. the alternator not charging. on that point of distance i tried to blast the audio but it still not charging. instead the car goes like slower with vibration.... if i on air con , headlight or wine up or down the windows the voltage goes 14+v and if i stop any of it, the voltage goes down to 12v when i light press my acceraltion to maintain below 80km/h. Bro thanks for some advice really appreciate it.

 

Are you suspecting a 5 month old battery being bad? I'm not saying thats impossible. I think what he is worried about is the 12.6v when the car is on and alternator running.

A fully charged battery at rest should be about 12.8v @ 80F. I like to check each cell with a hydrometer rather than just rely on a starting current test. I can do it without taking it anywhere and if the battery is bad, not all the cells will read the same.

 

Goodness... why are people encouraging the OP to worry?

It's called a 12 volt system for a reason.

If the voltage drops to 10, then let's worry. But so long as it's between 12 and 14 (and I'm not saying 12.00 to whatever decimal, just "around" those) voltages, it's fine.

 

I monitor voltage with my ScanGauge II and have remembered it always staying between 13.8 to 14.3V with the engine running the past two years. (I bought the car two years old so don't know if this was the case from day one with fresh battery) However starting about five days ago it started dipping down to ~12.4 for a few seconds and then would jump back to ~14.0. It would do it under varying engine conditions and varying times, a true intermittent. Then the next day I got a very slow crank condition so checked the battery. Was near normal 12.6V at rest but when turning on the headlights it dropped into 10-11V range. Then had a load test done on the battery and it measured only 126CCA. Ok so clearly battery going weak and on borrowed time so I replaced it. All fine for one day, voltage consistant 14V while engine running. Then the following day I notice the voltage dipping down again intermittently to 12.5V almost the same as it did before.

So this is normal per the ELP comments above? If yes then why wasn't this happening for the past two years? Was my old battery so weak that it required constant alternator output to keep charged? Now with the new battery it doesn't so goes into ELP varying output mode? And why did my old battery start showing this same pattern during it's final days? I put in the new battery to be safe for a cross country trip but didn't leave yesterday as I'm now worried about an alternator problem on the road. I will be driving through the night across barren country with services few and far between so don't want to get stranded.

Anyone with a real time voltage meter installed please comment on what your normal voltage fluctuations are.

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At idle, with low electrical load the Electrical Load Detector (ELD) signals the ECM to drop the alternator field current, basically idling the alternator and letting the car run off the battery.

You should notice a slight bump up in RPM when the headlights are turned on (ECM increases idle speed and restarts alternator's field current).

Here's what I could glean from the shop manual. link

 

This could explain why after installing the new battery I got a consistant 14V as it was at night with the headlights on. Also maybe I've never noticed this before as I run the A/C year round 95% of the time. Only a couple months here in the winter that it is not needed, but even then the defroster is needed which runs the A/C. I would think the A/C running is enough load to force 100% alternator output.

I will go out now and try different load conditions to verify all this. Idle, high rpm, radiator fan, A/C and fan, headlights, etc.

Edit: this is the first fall/winter I have been extra careful to not run my A/C. Previously I never opened the windows and never opened the outside air vent to keep out dust. I always used recirculate mode even in the winter. But after realizing a couple months ago that the A/C took away a full 3mpg I've changed my habit, hence partial reason for never seeing this voltage fluctuation before.

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Do you notice your headlights pulsating? I had a similar problem and replaced the alternator at 70K miles and voltage and other problems were fixed. You could replace the brushes but the process of doing it looked complicated.

 

No pulsating lights and all other electronics operating normally also. I think Steve244's post is exactlyspot on what I've been observing. I went for a drive and every time the voltage dropped below 14V I turned on the headlights and it shot instantly back up. With A/C on it seemed to delay the below 14V drop but then it did happen once or twice. Again once the headlights switched on voltage went right back up and stayed. Never had any change in voltage while lights were on.

I'm satisfied now and will start my 1,600 mile drive to CA in a few hours. Wish me luck and Merry Christmas to all.

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Made the drive without issue. Thanks Steve244 for the reassurance and saving my Christmas. As soon as I figure out how to send Rep points you'll get all I have available.

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L15A fit, what is normal voltage when engine idle/no load and with load (a/c on, headlight)

thanks