My new-used 03' Accord is doing something strange. When driving at night with either low or high beams, the headlights go from bright to dim (or dim to bright). Which ever! This is bugging me as I am concerned that they may go out completely. Any suggestions or ideas? Thanks for allowing this post.

 

how old is your battery? if its dying or can't hold the charge then it might make your lights dim when you let off the gas because the alternator isn't putting out much as much it does when your driving.

 

I did check the battery strength with a hydrometer and it seems ok. I am going to check it with a volt meter...it was replaced by the previous owner about a year or so ago. The problem occurs as I am driving at city and highway speeds. It seems worse when I am slowing down. I haven't yet had the alternator tested. Thanks for the help!

 

you need to load test the system............

are your lights dimming when the RPMs drop? If so, it may be time for a new alt or battery. The accord uses a split design where part is dedicated to charging the battery and part is dedicated to running the car.

Load testing will tell you where the problem is

 

OK, I've had the system "load tested" and during the test the voltage dropped down from about 15 volts to about 11 volts. I had this done at two parts places and neither one of the "parts professionals" could explain this phenomenon. I want to say that this corresponded with my having "let off" of the throttle during the test but I'm not positive . I did replace the ground cable with 2 guage replacement albeit a little more than twice the length of the original. I also did the PCM re-learn procedure. It did seem to hold the 14.5 - 15 volt level a bit longer before the voltage suddenly dropped to about 13 as indicated by my plug-in digital volt meter. I'll have to wait till tonight to see if this will correspond to the headlight issue. I do thank you for any and all help with this problem.

 

Do you have a thumping system in your trunk? Amplifiers take a lot of the juice while driving.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Importn2oRacer &raquo;</TD></TR><TR><TD CLASS="quote">Do you have a thumping system in your trunk? Amplifiers take a lot of the juice while driving. </TD></TR></TABLE>

That's why you run a capacitor....

 

Yea I know... but not too many people are willing to spend the 100 bucks for one...

 

ur alt is toast and possibly the battery

 

any other problems? check battery, alternator, voltage regulator, ground wire, and look for any visible shorts..

seems like a strange problem.. good luck!

 

most likely voltage regulator and that is built into the alt.

 

The problem is most likely the alternator. But, probably a bad diode and/or winding, etc. in the alternator. If it was a bad voltage regulator, the usual failure would be a failure to charge; so, it probably is not the regulator.

Replace the alternator...

 

failure to hold a voltage would cause the dip to below 12V.............I have seen many regulators fail and the classic symptom is voltage is too high or dips when under load.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by YeuEmMaiMai &raquo;</TD></TR><TR><TD CLASS="quote">failure to hold a voltage would cause the dip to below 12V.............I have seen many regulators fail and the classic symptom is voltage is too high or dips when under load.</TD></TR></TABLE>

Failure to <U>hold</U> a voltage would not cause it to dip below 12 volts (voltage regulator does not <U>hold </U>voltage). Voltage too high doesn't appear to be his problem. The dip is probably not caused by the voltage regulator. A regulator cannot compensate for low voltage. It's purpose is to provide the appropriate supply voltage.

 

OK, I have bought the darn alt. ($175@Advance by the way w/LLT warranty). If and when I can get back from my wife I'm puttin' it in although the ELD (Electrical Load Detector) or maybe even the PCM (Power "CRAZY" Module) could be malfunctioning. Well, at least I'll eliminate one of the three. I don't know why but the vehicle speed, not rpm, at 50 to 51 mph seems to be when I have the voltage fluctuation. Go figure!!! I'll post again after I change out alternator.
THANKS!!!

 

lol come back when you actually have taken some classes in electronics

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redbull-1 &raquo;</TD></TR><TR><TD CLASS="quote">

Failure to <U>hold</U> a voltage would not cause it to dip below 12 volts (voltage regulator does not <U>hold </U>voltage). Voltage too high doesn't appear to be his problem. The dip is probably not caused by the voltage regulator. A regulator cannot compensate for low voltage. It's purpose is to provide the appropriate supply voltage.</TD></TR></TABLE>

if one of the rectifier diodes failed in the regulator the voltage would definately dip. Thanks for playing. A voltage regulator will try to maintain the voltage that it has been set for if it cannot, you get sy

 

Well, I've seemed to resolved my electrical issue by taking the advice given. Thanks to all for all. Happy motoring!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1993solace &raquo;</TD></TR><TR><TD CLASS="quote">Well, I've seemed to resolved my electrical issue by taking the advice given. Thanks to all for all. Happy motoring!!! </TD></TR></TABLE>

Can we asked what solved the problem?

 

if the 7th gen cars are like the 6th gen you can reset the multiplexor by turning every thing off in the car (accessories) and then setting the intermiiten wiper ring to the middle position and turn the car on but do not start it. after 10 sec turn car off

 

Buy a Kinetik battery (power cell). Best investment. I and Kinetik recommend HC1400. Good luck.