Honda OBD1 Alternator control

[not-a-number]

I have installed an OBD1 alternator from a honda prelude in my lotus and not sure how to get it working. It has 4 wires that go to the original computer and then the main power wire.

I dont know how these work. Do they require a signal from the computer to turn on and regulate? At the moment it is not charging at all.

Can MS2Extra do this control?

I havnt had any luck on google, all i can find is how to convert from OBD0 OBD2 etc.

Any help or an idea of how they word would be great.

[matthewb]

I would guess that that alternator does not require any control from the computer. Is there a brand on the alternator? Do you have a picture of the connector? Have you searched the internet much for wiring? The Nippon denso alternator wiring schematic is very available online. Maybe with a little more info we can help you out.

[nismoautoxr]

here ya go but Im sure you have probably got it working by now since this was a month ago.

FR is not needed...its a input to the PGMFI for a feedback signal
S is battery voltage..can be looped around tot he battery stud on the alternator
IG is a switched voltage source that is hot in crank and run
L is the field and should be run to the charge bulb...the other leg of the bulb should be to switched voltage hot in crank and run

The most important of these is S and L.

L and IG can be tied together if not using a charge bulb but you wont have a telltale lamp if you do that so best you wire L to a bulb so you can tell if its charging or not.

Good Luck.

[Monzsta]

I used a spare output to utilize the high/low charging feature like the stock pcm does. By default it charges at 12v (float charge) then when you trigger the regulator wire it switches to 14v. Nice for a bit of fuel economy. I'll see if I can find that article on Honda dual charging system.

EDIT: here it is.

http://opensiuc.lib.siu.edu/cgi/viewcon ... =auto_pres

My strategy was to have the 12v enabled during light throttle cruise conditions (<20% throttle) and engine up to operating temps. The factory used the electronic load detector to see high amp loads (lights, defroster grid, wipers, ect ect) as an input but I was completely out of ins/outs on the msII so I didn't use it as much as I wanted to.

It's the C wire that has to be brought high for 14v. If it's brought low 12v is enabled.