Rectifier on the fender

[e3steve]

With 5 wires to it and, assuming there's no rec anywhere else on the bike's system, I'd say that that's a rec/reg. If it was just a rec then it would have only 3 (or maybe 4, not relying upon the heatsink for grounding) wires.

[jensen]

Hi Bech,

I bet it is a voltage regulator, for what it's worth.
Where does the red wire connect too ?

Jensen

[bech]

There is no other rectifier on the system.
There are 5 wires but just 4 connected.

The red/white connects to the battery positive.
The pink and the yellow to the alternator.
The green to the indicators.
According to the diagram the green and the yellow should connect to a regulator as well. They don’t.

[jensen]

Hi Bech,

??????, esteve what would be you're comment on this ?

Jensen

[e3steve]

Green is ground, Bech; are you sure it doesn't go to earth? That would make sense. Looks like a 'potted' silicon-diode rectifier, in that case.

[bech]

You're right, Esteve. The green has a split which grounds.
The diagram shows the green going to front and rear indicators where it grounds also.

So is it a regulator as well?
What's a 'potted' sd rectifier?
Should I ignore the unconnected yellow?
Is it an improvement to have the rectifier moved from the battery box?

Thanks.

[e3steve]

I can't see, from the photo, if the unused yellow actually enters the epoxy compound ('potting' -- I hope that answers another question). Early rectifiers were selenium diodes; this type has a 'natural' tendency towards attenuating (cutting down) the passing of current. This attenuation was taken into account at the design stage, thus balancing the rate of charge at a level acceptable to older lead-acid battery technology.

'Things' have moved on.

Modern batteries are more tolerant of higher charge rates. I've experimented with silicon- and Schottky-diode rectifiers, along with the current-saving measure of using an LED taillight bulb. And I ride with lights on, thus a higher constant charge rate.

Look through my past posts under this subject heading.

Should I ignore the unconnected yellow?

If it works, then 'yes'. If the rec is non-standard (i.e. not correct for your model of CB250) then the additional yellow is probably common with the 'other' yellow, being used as a junction for the particular application on the model for which it was designed.

Is it an improvement to have the rectifier moved from the battery box?

Possibly. It will run cooler because it's in free air and it's bolted to a huge heat sink -- the fender!

The charging system works well but can be improved upon. I, and others, have posted extensive -- possibly excessive -- words on the subject. Please look back to mid-2008 onwards in Electrical - Wiring here.