Honda rectifier / regulator "extra" wire?

[9D280]

Quick background - I am replacing the rectifier on the Merc with a Honsda Rectifier / regulator unit after I hooked up a voltmeter to the original kit & found I had a 20 odd volt charge!

So, having recieved the unit, I can account for all the wires bar one. I have looked at umpteen websites reportedly showing Honda wire colours, but none show a plain white.

I have:
Single black with eye connector - Earth

2x grey with a male - from the coils.
1 x grey with a female - tacho connection
1 x white / black stripe with a female - +V to charge
(Those 4 being bundled in one loom)

The puzzle is I also have a white with a male that pokes out the bundle loom about halfway down. What is it? I reckon it's either an overheat or low charge signal wire - but as a male I expect it to take power rather than give a signal. But then it could be the overheat sinks voltage to the earth. Is it maybe a reference voltage for the regulator for a clever charging system?

Can anyone shed any light? I believe the unit is off a BF50.

[9D280]

OK, Fi-i-i-inally found a diagram in the back of an online owner's manual. Such a good scan it took 3 prints and a highlighter pen to follow the wires round it, but turns out my guess was slightly wrong.

Black / white feeds the ignition switch, the plain white feeds the battery (via the Starter solenoid).

Now makes sense why it's a male connector!

Still makes no sense why I can't find reference to a white wire on the colour charts. Guess it's off a newer or older engine than the published stuff.

Fun bit now is going to be where to mount it!

[m chappelow]

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Fun bit now is going to be where to mount it! [/QUOTE]

Ideally on something solid so the heat can dissipate with plenty of air circulating for best results ,

I retro fitted a rectifier for use with a yamaha outboard that dident have one fitted ( it just had a coil fitted with 2 wires coming out ) with a kawasaki motorcycle one many years ago just needed it for charging a 12 volt battery to run some Nav lights .

One of the white wires on that one was redundant and not used as it was taped up by the auto electrician that gave me and he said I only need 4 wires in use

Mounted the rectifier under the jocky seat near the battery .

[9D280]

Yeah, I toyed with a "console mount", but having mucked about under the hood last night, I have 2 possible options:

1) tie wrap / goop it to the air intake "toobs" o nthe port side.
2) drill & tap the air box on the starboard side by the starter.

I am sorely tempted by #2 for 2 main reasons - firstly on the air intake toobs it contacts the case, although with the air being ingested it should be kept nice & cool. The air intake box is cast from aluminium alloy, so it should act as a nice heatsink, and the geometry seems to hold the outer side of the unit in relatively clear air. Current plan is to drill & tap, loctite a couple of M6 screws in from the inside, and then mount it on the resulting spigots. That way will also keep the bolt holes sealed.