2004 Accord coupe: Proper charging voltage

What is the proper charging voltage value while driving?
Can it fluctuate between 13.0V and 14.2V, almost randomly?

I have noticed my headlights getting randomly dimmer
during driving at night, so I got a cigarete lighter
pluggable volmeter to monitor voltage and I see it
vary mostly between 13.8V-14.05V but sometimes it
plunges to 13.0V to quickly recover throug 13.2, 13.4 back
to 13.8V... Can a turning on A/C compressor cause this?

Is this normal or my battery or alternator is going down?

I had two japanesse cars before this honda, one was
1994 nissan sentra, the other is 1995 toyota camry
(still got this one) and neither one has any visible
dimming on the headlights nor voltage drops like this.

Pszemol wrote:
> What is the proper charging voltage value while driving?
> Can it fluctuate between 13.0V and 14.2V, almost randomly?
>
> I have noticed my headlights getting randomly dimmer
> during driving at night, so I got a cigarete lighter
> pluggable volmeter to monitor voltage and I see it
> vary mostly between 13.8V-14.05V but sometimes it
> plunges to 13.0V to quickly recover throug 13.2, 13.4 back
> to 13.8V... Can a turning on A/C compressor cause this?
>
> Is this normal or my battery or alternator is going down?
>
> I had two japanesse cars before this honda, one was
> 1994 nissan sentra, the other is 1995 toyota camry (still got this one)
> and neither one has any visible
> dimming on the headlights nor voltage drops like this.

voltage is in the correct range. look for bad connections. you don't
state mileage, but alternators are usually good for 100k+ miles. check
belt tightness too.

"jim beam" > wrote in message ...
> voltage is in the correct range. look for bad connections.

Bad connections where?

> you don't state mileage, but alternators are usually good for 100k+ miles.

milleage is less than 50k.

> check belt tightness too.

OK. Where can I get a repair manual for that accord?
Is there an electronic (pdf) version of the manual available online?

Pszemol wrote:
> What is the proper charging voltage value while driving?
> Can it fluctuate between 13.0V and 14.2V, almost randomly?
>
> I have noticed my headlights getting randomly dimmer
> during driving at night, so I got a cigarete lighter
> pluggable volmeter to monitor voltage and I see it
> vary mostly between 13.8V-14.05V but sometimes it
> plunges to 13.0V to quickly recover throug 13.2, 13.4 back
> to 13.8V... Can a turning on A/C compressor cause this?
>
> Is this normal or my battery or alternator is going down?
>
> I had two japanesse cars before this honda, one was
> 1994 nissan sentra, the other is 1995 toyota camry
> (still got this one) and neither one has any visible
> dimming on the headlights nor voltage drops like this.

You haven't said whether these readings were obtained
at tick-over, cold; tickover, hot; or at usual running speed
ie. >2000 rpm.

At low revs, the alternator is pushed to supply higher load
current and the battery is used as a fall-back. Consequently,
its voltage is likely to fall a little while making up the shortfall.

HTH

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"Pszemol" > wrote in :

> What is the proper charging voltage value while driving?
> Can it fluctuate between 13.0V and 14.2V, almost randomly?
>
> I have noticed my headlights getting randomly dimmer
> during driving at night, so I got a cigarete lighter
> pluggable volmeter to monitor voltage and I see it
> vary mostly between 13.8V-14.05V but sometimes it
> plunges to 13.0V to quickly recover throug 13.2, 13.4 back
> to 13.8V... Can a turning on A/C compressor cause this?
>
> Is this normal or my battery or alternator is going down?
>


Is your Check Engine light on?

There is an important question.

--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"Graham W" > wrote in message ...
> You haven't said whether these readings were obtained
> at tick-over, cold; tickover, hot; or at usual running speed
> ie. >2000 rpm.

Not sure what tickover means... and hot to test :-)

I see lights going dimmer for a while when cruising at the
city streets, usualy at around 40mph. Rpms are below 2000 then,
around steady 1600 or so. It is 4 cyl 2.4l engine (EX-L model).

> At low revs, the alternator is pushed to supply higher load
> current and the battery is used as a fall-back. Consequently,
> its voltage is likely to fall a little while making up the shortfall.

Well, I have never observed drop below 13V, but still - as
I said before, this it the first car I own which does it.
I just wrote to check if these hondas do it, and if this
normal, or is an early sign of battery being old (probably
an original honda battery from 2004) or something else.

Did not have a chance to chec the belt yet, maybe it is
loose and when compressor wants to start it slips causing
alternator to stop turning as well... However I hear no noise.

"Tegger" > wrote in message ...
> "Pszemol" > wrote in :
>
>> What is the proper charging voltage value while driving?
>> Can it fluctuate between 13.0V and 14.2V, almost randomly?
>>
>> I have noticed my headlights getting randomly dimmer
>> during driving at night, so I got a cigarete lighter
>> pluggable volmeter to monitor voltage and I see it
>> vary mostly between 13.8V-14.05V but sometimes it
>> plunges to 13.0V to quickly recover throug 13.2, 13.4 back
>> to 13.8V... Can a turning on A/C compressor cause this?
>>
>> Is this normal or my battery or alternator is going down?
>
> Is your Check Engine light on?
>
> There is an important question.

No, it is not... Should I expect this light goin on for
a battery or alternator problems??? That is a surprise.

"Pszemol" > wrote in
:

> "Tegger" > wrote in message
> ...
>> "Pszemol" > wrote in
>> :
>>
>>> What is the proper charging voltage value while driving?
>>> Can it fluctuate between 13.0V and 14.2V, almost randomly?
>>>
>>> I have noticed my headlights getting randomly dimmer
>>> during driving at night, so I got a cigarete lighter
>>> pluggable volmeter to monitor voltage and I see it
>>> vary mostly between 13.8V-14.05V but sometimes it
>>> plunges to 13.0V to quickly recover throug 13.2, 13.4 back
>>> to 13.8V... Can a turning on A/C compressor cause this?
>>>
>>> Is this normal or my battery or alternator is going down?
>>
>> Is your Check Engine light on?
>>
>> There is an important question.
>
> No, it is not... Should I expect this light goin on for
> a battery or alternator problems??? That is a surprise.
>



There is a known issue with your model having to do with fluctuating
charging voltage and headlights dimming. Sometimes a P1298 is stored in the
ECM.

TSB 05-034 covers this for ALL '04 Accords..

The most likely source of your problem is cracked solder in the Electrical
Load Detector (ELD). This means you must replace the entire underhood fuse
box. The ELD is potted, so it's not fixable like a Main Relay.

You may want to run this past your dealer and see if you can get this done
under some kind of warranty, official or unofficial.

--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"Tegger" > wrote in message ...
> There is a known issue with your model having to do with fluctuating
> charging voltage and headlights dimming. Sometimes a P1298 is stored
> in the ECM.
>
> TSB 05-034 covers this for ALL '04 Accords..
>
> The most likely source of your problem is cracked solder in the Electrical
> Load Detector (ELD). This means you must replace the entire underhood fuse
> box. The ELD is potted, so it's not fixable like a Main Relay.
>
> You may want to run this past your dealer and see if you can get this done
> under some kind of warranty, official or unofficial.

Interesting...

One more electrical question - when I open the hood, near front
driver side shock absorber column there is a small rectangular box
with three LEDs with "Corrosion Control Systems Auto Saver Device"
written on the sticker.
What exactly is it, how it works and is it factory installed or
some aftermarket gizmo the previous owner put in?

"Pszemol" > wrote in
:

> "Tegger" > wrote in message
> ...
>> There is a known issue with your model having to do with fluctuating
>> charging voltage and headlights dimming. Sometimes a P1298 is stored
>> in the ECM.
>>
>> TSB 05-034 covers this for ALL '04 Accords..
>>
>> The most likely source of your problem is cracked solder in the
>> Electrical Load Detector (ELD). This means you must replace the
>> entire underhood fuse box. The ELD is potted, so it's not fixable
>> like a Main Relay.
>>
>> You may want to run this past your dealer and see if you can get this
>> done under some kind of warranty, official or unofficial.
>
> Interesting...
>
> One more electrical question - when I open the hood, near front
> driver side shock absorber column there is a small rectangular box
> with three LEDs with "Corrosion Control Systems Auto Saver Device"
> written on the sticker.
> What exactly is it, how it works and is it factory installed or
> some aftermarket gizmo the previous owner put in?
>



It is a ripoff.

Is an aftermarket gizmo that does not much more than make the seller rich,
and damage your factory wiring.

It's supposed to work on the same principle as similar devices that have
been installed on boats for years. But a car is not a boat and is not
immersed in water, so the principle doesn't work.

--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/