Topic: hooking up a "modern" regulator/rectifier *need help fast!!! please!*

[CETME]

Hey guys....  My rectifier doesn't show any resistance... so I went to the Junkyard to find another one.  Didn't find one.... So then the junkyard owner told me to hook up a regulator/rectifier from a newer honda, claiming he does it all the time, and that its much better than the "old crap"

Seeing as i'm leaving for Alaska on Sunday, I was running out of options... I took one off of a newer Honda.

There are two groups of wires on this RR... the first set has Red, Green, and Black wires.  I assume that the green and black go to the regulator wires.... but there is still the white wire from the alternator... but this RR has no white wire.

The second set of wires go to the rectifier, and these are three yellows, a red and a green....  Here I assume that I connect the three yellow field coil wires to the three yellow RR wires... then the red wire to the red wire of the first set of wires... and the green to nothing? (as its already connected in the first place to the regulator)

I'm still stumped as what to do with the white wire from the alternator... what do I do about this one? any ideas? suggestions?

[bryanj]

The later units DO NOT MATCH colour to colour with the earlier looms. Somewhere i have a diagram on how to connect this but i cant find it right now.

[Bob Wessner]

Would a 550 wiring diagram help?

[CETME]

Would a 550 wiring diagram help?

Bob, I have a wiring diagram in front of me, but I dont know which wire connects to which from the alternator to the new RR.

Bryan, if you can find that diagram, i'll be your best friend!

[CETME]

OH! if I had a diagram from a 80ish bike (is this what you were talking about Bob?)... I guess I could figure it out..... I'm searching on the web for it...  but if anyone has a wiring diagram from an 80's CB, let me know!

[Bob Wessner]

No, sorry, it is not a later diagram. I see your point. Good luck finding some info and getting on the road.

[TwoTired]

Do you know just what bike your replacement unit is from?  If I could see how it was wired into the original bike, I could figure out how it could work in the CB550.

Some of the CB's had Permanent magnets in the alternator instead of the Field coil you have in your bike.
If your RR is from one of those, it is unlikely to work on your bike since it won't provide the control current for the field  (the white wire).

[the_genrl]

heres a picture.  you can make this out of 6 high current diodes or 2 bridge rectifiers.  black wire (-) goes to ground and the red wire (+) goes to the regulator.  3 yellow go to the alt. 

[Bodi]

I know little about newer bike electricals, but...
The 3 yellow wires must be the stator coils. Black is pretty much Honda's color for ignition power, but later models might have changed. Red is normally the battery connection. Green is usually ground to the rest of the world but I don't know for sure about Honda. So the mystery is twofold:
Is this a reg/rect for an induced field alternator?  It might be for a unit with unregulated alternator, that regulates the output power with a pass transistor or using pulse width control. This is the more elegant solution to the Lucas zener diode "regulator".
If it IS for a field controlled alternator, the red wire is 99% likely to be the battery wire, so black and green wire remain and it might ground through the mounting bolts too. Probablybly the black wire is ignition power, allowing the regulator electronics to not use power when the key is off. Looking at the electrex replacement units they have a red, black, and YELLOW wire; maybe your green is field although nobody should use green for non-ground wire IMO.
You could experiment a bit and see. The red should show diode-like behavious to the (unconnected) yellow wires (an ohmeter will show low one way and high the other). If the yellow wires show the same sort of pattern to the mounting bolts then probably the unit grounds through them.. so it has to be screwed to the frame to work.
So, if the red is battery and ground is via the case: See if there's resistance from the black wire to ground. If there is - but not a low/short reading - then try it as ignition power. If it doesn't smoke or explode when switched on, see if the green wire has battery power on it. If so, connect the yellow wires and try connecting a cliplead from the alternator field wire directly to the battery + terminal and starting the engine - revving should drive the battery voltage above normal as the alternator is making 100% power. If the battery voltage goes above 14V or so and the green wire IS the field, the voltage on it should drop down to zero or a few volts. If that happens, you have it figured out and can connect green to field and try it out for real.

[CETME]

Thanks guys for all the help!...

I took the easy way out and ordered an Electrex RR......   IF this bike has to make it to Alaska and back, I better not risk it........

[750FSS]

HEY CETME

YOU are riding from FLA TO AK?  BOY YOU ARE HARD CORE!!! 

[CETME]

HEY CETME

YOU are riding from FLA TO AK?  BOY YOU ARE HARD CORE!!! 

LoL.. or stupid....

Had another Motorcyclist say I was "Underbiked" for the trip.... I thought that was odd.... the 550 has some power... not like my Ducati.. but it seems like it would run 80mph all day long no problem....

Any thoughts on this??

[TwoTired]

The only way you would be under biked is if you over loaded the thing.  If you were carrying more than 400 pounds combined weight rider and gear, the bike will handle top heavy and crosswinds could be interesting.  The motor will do 80 all day long.  The chain will need frequent lubrication and adjustment.  I should think daily.  And, if a new chain is on old sprockets, it will probably not make a round trip, as a guess.

Have you checked the cam cover for rocker shaft wear?  CB550s prior to mid 76 sometimes wear out the cover.  Somewhere between 20k to 30K miles, the bearing surfaces of the rocker shafts wear abnormally.  This ruins the geometry and screws the rocker and camshaft if not caught in time.  That's the only engine issue to be concerned about.  Once the shafts are prevented from turning in the cover, it's rock reliable.

[bearcatamo]

Where in FL are you? I have a friend that made that ride a few years ago. He rode a late model Nighthawk, the guy he rode with rode an older GL. It took about 2 weeks round trip.

Barry in FL

[TwoTired]

Hey guys....  My rectifier doesn't show any resistance...

It is very odd that all six diodes in the rectifier have failed open.  Some yes. All
Did it encounter a lightning strike?
What meter are you using? Does it have a diode setting? If so, check the rectifier with that setting.  The diodes need a .6 or .7 volt differential voltage applied to them in order to conduct. Without it, it will read very high resistance.

[CETME]

This is the meter i'm using.....

I tried it on the diode setting, and got nothing......

[TwoTired]

Looks like decent meter.  Did you try to measure each diode and then reverse the leads and measure again?

Did you try to run the engine and disconnect the battery while it was running?
Don't.  That is one way to fry the rectifier.

[carsholduptraffic]

as you should be on the road by now, i'll just say i hope it works. at least you have a lot more people around in your part of the world!!! {compared to a similar trip in oz)

[BigLoser]

Along these same lines does anyone have an opinion on which brand is better Electrex RR or Oregon motorcycle parts?

New user--- 750K0 and 750K1 which I bought both this week in seperate deals-  I'm allready an addict!

[Bob Wessner]

[I'm allready an addict!/quote]


No, no, it's aficionado. 

[TwoTired]

[I'm allready an addict!/quote]


No, no, it's aficionado. 

I wonder if the term "denial" applies here?

[Bob Wessner]

I wonder if the term "denial" applies here? 

Maybe just a little. 

[.RJ]

To the top!

So, in doing some more research while I wait for some parts, I'd like to use a "modern" R/R unit on the bike.  I'll be building my own harness, and I have some spare F4i parts.  The wiring circuits look to be executed more or less the same, except for a white wire from the alternator - whats its purpose, and will this prevent me from using the modern piece?

F4i alternator and R/R wiring:



Comapred with CB750 K1 Wiring (my bike is a '71)

[TwoTired]

white wire from the alternator - whats its purpose, and will this prevent me from using the modern piece?

The white wire provides voltage to the alternator to energize the electromagnet.

It looks like your F4i has a permanent magnet which has no control.  I don't expect the "new" one you've chosen will work with the SOHC4. Sorry.

Cheers,

[.RJ]

D'oh!

Thanks though

Do you know of any self-contained R/R units that can be wired in with the 750's alternator?

[TwoTired]

This place has gotten good reviews on this site.  No personal experience, though.

Cheers,

http://www.oregonmotorcycleparts.com/Reg_rec_units.html

[.RJ]

Ouch - pricey.

I gotta think about that one - thanks for the link!

Edit - this may do - its from a CB900F

[TwoTired]

Ouch - pricey.

I gotta think about that one - thanks for the link!

Yeah, that's kinda what I thought, too.  Probably, why I keep using the original types I suppose.  I really haven't looked much for replacements.  The original stuff is still working fine in all my bikes.

Cheers,

[Pinhead]

Hey, TwoTired: What do you think of the regulator/rectifier in my sig?

[oldfart]

white wire from the alternator - whats its purpose, and will this prevent me from using the modern piece?

The white wire provides voltage to the alternator to energize the electromagnet.

It looks like your F4i has a permanent magnet which has no control.  I don't expect the "new" one you've chosen will work with the SOHC4. Sorry.

Cheers,

In simpler terms, you cannot wire a reg/rect designed for a permanent magent alternator to a system having an electromagnet alternator, or visa-versa.  There just isn't any way, because the regulator portion is activated in a totally different manner.  The permanent magnet type regulator actually shorts the stator to control charge, while the electromagnet type regulator turns on and off the alternator's electromagnet.  Very different systems.  For reference, there are very few bikes made today with the older electromagnet design.  Probably 95 percent are permanent magnet now.     P.S. Yes, the 900F one will work on an SOHC 750, but the color codes won't match even though both are Honda, because when Honda went solid state in the late 70s they moved the regulator from the positive side of the field coil to the negative side, hence the regulator has differing wire colors. 

[TwoTired]

Hey, TwoTired: What do you think of the regulator/rectifier in my sig?

I don't know. Never tried it.  The web pointer shows it at almost $50.   It would be more interesting at $16.

All my mechanical regulators are still working without any additional expenditures.  And, I have spares on hand that will fit right on the bike without any adaptors or mount issues.  I simply don't have much incentive to try it out.  Sorry!

Cheers,

[bryanj]

Try this attachment

[.RJ]

P.S. Yes, the 900F one will work on an SOHC 750, but the color codes won't match even though both are Honda, because when Honda went solid state in the late 70s they moved the regulator from the positive side of the field coil to the negative side, hence the regulator has differing wire colors. 

Will I need to do any additional work, other than getting a CB900 wiring diagram and matching up the wires?  I'm building my own harness here, so thats not much of a concern.  The harness that came with the bike looks more like a fire hazard than an electrical harness.

[oldfart]

All the wires are there, you just need to know which are the right ones.     The following link should help.

[Pinhead]

I don't know. Never tried it.  The web pointer shows it at almost $50.   It would be more interesting at $16.

Holy smokes! It's still ~$13 here at zip 66212!

[TwoTired]

I don't know. Never tried it.  The web pointer shows it at almost $50.   It would be more interesting at $16.

Holy smokes! It's still ~$13 here at zip 66212!

I didn't give the site my zip code as I recall.  (but maybe, I did) mine's 95035
Partsamerica.com  Free shipping over $50
Part number VR301
Retail Price:   $72.57
Our Price:   $47.99
You Save:   $24.58

Cheers,

[Pinhead]

Holy cow,  you're right! I put in your zipcode and it came up to $47.99. What a crock of horse#$%*!! It's the exact same part that I get for $12.96!!!