[QUOTE=Ek9,Jul 21 2006, 12:23 PM] Keep in mind that the ECU controls the alternator and turns it off from time to time. Honda's have done this for years.

 

Who's talking about the sensors? Reduce the voltage on my coils and you reduce the potential output voltage. Ditto for the fuel pump. I want them running at their rated voltage. I didn't like seeing the head lights dim and brighten as I was driving around either. Now, if they used it to cut out the alternator when I accelerated hard, then it might be worth something. My experiments show, they don't though.

It doesn't really matter, either the headlights, or the interior fan's enough to keep the alternator turned on all the time. Looks like it's more aggressive on the economy car's than on the '2k. Might be a sign my battery's weak though.

I'd think you FI people would be on the bandwagon? Cut the voltage to the coils and all of a sudden you might get mis-fire under boost. A common performance trick's to boost the voltage to the coils to over 14v's.

 

No thanks, I'll keep the stock PCM controlling Alternator output.

 

 

I'm kind of surprised at your attitudes but, what the hell.

Whether you like the idea or not, back to the original poster, seeing 12.6 volts while cruising down the road isn't unusual BECAUSE the ECU controls the alternator. At this point there are no symptoms that your alternator is bad.

 

"Slows2k" is a professional S2000 tech with access to all of Honda's technical writings and specs for everything to do with this car. There are but maybe only 2 S2000 "pro" EXPERTS that regularly post on this forum and he is one of them. (And no, I'm NOT the other.) Whatever he and the other guy says, I will believe without question. Anyone else (including myself) is relying upon past experience based on a lot of "other car" and S2000 knowledge, some of which do not always apply to every S2000 situation.

 

That's out of the Honda S2000 Service Manual. I just read it and posted what I read. It is now apparent that the Honda Service Manual leaves a lot of details out - I'm learning a lot about our car's electrical system just by reading this thread.

 

I think we'll find with almost any service manual, that there will be misprints, aborations and odd bits of information. On the most part, the Helm service manual is pretty good.

 

It's says:

"Is the voltage over 15.1?

Yes: replace the rear housing assembly.

No: go to step bla bla"

Page 4-23. So, over 15.1 is a problem.

The honda service manual is the best manual I've ever read.

The nice thing too is the commonality between all honda's. The S2000 charging system is identical to the Civic and integra ones down to the color codes of the wires. If you know one, you pretty much know the other.