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Guru call: 4-pin alternator plug from S2000/F20C connection?
ElmrPhD - 10/3/16 at 10:28 AM

Dear modern automotive electronics gurus,

Trying to put a 2005, UK-spec' Honda S2000/F20C motor in my MNR road-legal track toy.

What to do with these 4 wires?

I'm too old(-school) to understand so many connections coming from a generator... And these 4 wires are in addition to the main, fat power output to the battery. None are a simply a ground. The alternator is grounded through its direct mounting to the block.

The 4-pin plug's pins are:
1 - "IG" which eminates from the fuse box, switched power, but also branches off to the ELD (Electrical Load Detector) unit.
2 - "C" which goes to the ECM (main brain) and is termed "Alt Ctrl Sig"
3 - "L" which is the good old lamp wire going to the dash light (via a diode that I have to figure out)
4 - "FR" which goes to the ECM (main brain) and is termed "Alt FR Sig"

No, (at this point) I'm not using the original Honda ECM, which utilizes the ELD's data and that of the FR and/or C wires to tell the alternator whether it's a good time to put out all it can or just trickle charge or something in between.

Rather, I am (currently) planning on using the Omex 710 that I'd already bought for running a K20A2 (Honda Type-R Civic) engine.

I believe the Westfield/S2000 cars run this F20C/Omex combo', but they want money to join in their discussions...

Ideally, I could take over the decision process from the ECM/ELD with a simple switch (providing either ground or 5V signal to either the FR or C wire, from the contradicting things I've read) that says either "charge with gusto" or (in a sort of poor man's KERS way) "relax your charging efforts while I accelerate". Wouldn't that be cool?

If anybody knows what I should do with these 4 wires from the 4-pin plug, I'd really appreciate it. I know some have simply omitted the FR and C wires, but from what I understand, that leaves the regulator thinking it should charge at full chat the whole time.

I don't suppose the Omex can deal with the ELD can it?

THANKS!!!

Steve, in the NLs


theconrodkid - 10/3/16 at 12:03 PM

I feel your pain,would it not be easier to use an alternator off a Kabuto digger ,small,cheap and simple to wire up


ElmrPhD - 10/3/16 at 12:16 PM

Thanks Conrodkid.

I've thought about it and may eventually do that. That corner of the car is the heaviest, so I'd love to replace the big 105 Amp Denso unit with something smaller (I need, what, 40 amps?), but I'm struggling for time and already have all this original hardware in place. The biggest challenge (for me) would be fabbing up a mounting system as this one slides (tightly) into mounting ears of the block, rather than hanging off with any sort of adjustment mechanism. If I could relocate it down lower, at the same time, that would be wunderbar. Some day.
For now, I'd just like to get this aging project running.

So, what do I do with the C and FR wires??????????????????????

Thanks, again,
Steve


quote:
Originally posted by theconrodkid
I feel your pain,would it not be easier to use an alternator off a Kabuto digger ,small,cheap and simple to wire up


daniel mason - 10/3/16 at 08:41 PM

Or sell the omex and drop the Honda ecu and loom in there


BaileyPerformance - 11/3/16 at 09:21 AM

We have just mapped (yesterday) an s2000 in a mk2 escort.

We scrapped the factory ECU and installed megasquirt using all the factory sensors.

The alternator works fine without the factory ECU or control module, PM me your email address and I will email you the wiring details.


ElmrPhD - 11/3/16 at 04:18 PM

Oh, you are, indeed, DA MAN!!! (Whatever your name is...)


quote:
Originally posted by BaileyPerformance
We have just mapped (yesterday) an s2000 in a mk2 escort.

We scrapped the factory ECU and installed megasquirt using all the factory sensors.

The alternator works fine without the factory ECU or control module, PM me your email address and I will email you the wiring details.