Rep Power: 318

my dimming is not normal though, its not like a pulsing... it will just stay dim until i let off the gas, it's really annoying and shouldnt be happening

 
Rep Power: 812

well voltage fluctuates depending on if you're pressing the gas. I've had it where I could press the gas, voltage drops, release gas it jumps back up. I can even see the gauge moving up and down with each flash of the turn signal. In the winter, I've seen 15v+ when you first start the car. I really don't think you have a problem, and I bet thats what they'll tell you wherever you take it.

 
Rep Power: 318

that's exactly what happens to me

 
Rep Power: 812

well thats a problem of having a crap small alternator. A new one won't fix that unless you get high output or a rewind, which will prolly cause more probs and take away hp. In other words, all that is happening because your alternator can't output enough power even for just the cars own accessories, so then it switches to battery power. And thats how you get the dimming going from 14v alt to 12v bat.

 
Rep Power: 318

just to follow-up: well after a couple days my car runs good again. at night the gauges NEVER dim anymore and voltage stays around 13, still no 14 but i'm okay with that.. i'm just glad the dimming is over. looks like the problem was my battery.

thanks everyone!

 
Rep Power: 361

good. glad we could have helped!

 
Rep Power: 0

I've had my high output alternator for almost a year now and I've had no problems with it whatsoever. And even if one did have problems, most of the higher quality alternators come with lifetime warranties so no big deal? Yeah I may have sacrificed 10-15hp with it, but you only lose the horsepower if you're driving the alternator hard. Which I don't. Otherwise, I haven't noticed any power loss when listening to my stereo (at normal volumes), having the headlights, rear defrost, a/c all on at once. It's still pushing out 14.2-14.5 volts.

 
Rep Power: 0

More likely than not, the ELD is failing. Honda did a crap job designing the way the ELD functions, which has led to numerous people replacing batteries and alternators when they're not the problem.

FACT: If you're car is running a stock alternator at RPMs above 1000, you should have a voltage output of 13.5v - 14.4v (a high output alternator should always put out 14.2 - 14.5).

Follow the guide below to troubleshoot the ELD. I would recommend every owner of a civic running a high wattage system (>500w) to keep a spare ELD in the glovebox. They're around $30 and well worth it, as once you start seeing a voltage drop below 12v while the vehicles is running, your ELD is on it's last leg and will fail within a few days - a couple of weeks.

Steps (for 2001 - 2005 civics, should be similar for any year after)

1. Turn the car off
2. Disconnect the ELD 3P connector on the bottom of the underhood fuse/relay box
3. Turn the Ignition Switch on (II)
4. Measure voltage between body ground and terminal 3 (Grn/Red 01 - 05 Civics)
5. if there's about 5V, replace the ELD (if not continue to step 6)
6. Turn the ignition off
7. Disconnect ECM/PCM connector E (31P)
8. Check for continuity between body ground and ECM/PCM connector terminal E15 (01 - 05 civics located behind glove box)
9. If there's continuity, repair the short in the wire between the ECM/PCM (E15) and the ELD (if there isn't continuity, continue to step 10)
10. (Only do this step if you have DTC 1297 AND the above did not work - DO NOT pay to have a dealership update or program a new ECM/PCM unless you have DTC1297 AND the above DID NOT work) Update the ECM/PCM if it doesn't have the latest software, or substitute a known good ECM/PCM

 
Rep Power: 210

you do realize this thread is 9 years old right?