Topic: UPDATED: SOHC4 Electronic Regulator Replacement

[Pinhead]

I started a thread a THREAD way back in '06 about how to replace the expensive electronic regulator/rectifier and the old mechanical regulator with a modern automotive equivalent. At that time I used a Ford regulator since that was what I had on hand - and it was CHEAP.

I've since reconsidered my choice. Six years and almost 400 posts later I've decided to use a VR295, commonly used by Dodge. It only has two terminals (and a case-ground) so there aren't unused connections to get confused.

Attached is the picture and a diagram. I hope this will be much less confusing so more people can save themselves some money and a lot of headache.

This should work on all of Honda's field-regulated alternators. It wouldn't work on the permanent magnet alternators, but should work on any of Honda's three-phase systems that has a center coil, whether it's a coil on the side cover or an electromagnet coil on the crank end.  (500, 550, 650, 750, 900 1000, 1100, and probably more)

EDIT: The color codes don't coincide with any wiring codes on the motorcycles.

EDIT 5/30/2013: This regulator draws 10ma when idle with the key off. If you ride your bike every day or every other day, this shouldn't be a problem. However, extended periods of non-use will eventually drain the battery. Therefore I recommend feeding the "sense" wire through a relay. This could also be accomplished by tying both terminals together and running a single wire to a relay, as in the second diagram.

A VR124 regulator will work as well. I don't have wiring color codes yet, though.

[Pinhead]

The three-phase charging system that we have requires a three-phase rectifier which isn't included in the aforementioned regulator. Luckily it's simple enough to use a generic three-phase rectifier. Any three-phase rectifier will work as long as it can handle 35 or so amps and has a minimum peak-inverse-voltage of 24 volts. Most bridge rectifiers have PIV ratings at 100 volts or higher (mine is rated at 1000v) so you shouldn't have any trouble finding one that is suitable. The rectifier must be heatsinked. I mounted mine to a solid piece of angle-iron that extends the width of the frame (my ignition is also mounted to this) so there is substantial mass through which the heat can spread.

Wiring the rectifier is a lot simpler than it looks. The three wires that come out of the alternator are three-phase AC power. The rectifier will convert this power to DC.

Just to make it simple, I'll use the three-phase rectifier from above as an example. Three of the lugs will be labeled with a "~" which denotes AC power. The output of your alternator goes directly to these three lugs. The "-" lug goes to the "-" terminal of your battery and the "+" goes to the positive terminal. Since the regulator varies the output directly from the alternator, this is all you need to do with the rectifier.

[Pinhead]

Reserved

[Pinhead]

Reserved.

[Pinhead]

Reserved.

[RAFster122s]

So, you have 3 yellow wires coming from the bike's rotor.where do theyconnect or are you only replacing the regulator and not the rectifier?

[Pinhead]

So, you have 3 yellow wires coming from the bike's rotor.where do theyconnect or are you only replacing the regulator and not the rectifier?

The rectifier replacement is explained in the 2nd post. 

[vonvendetta]

Excellent, thank you! I see o`Reilly auto parts has it for $15.

http://www.oreillyauto.com/site/c/detail/MPI0/2VR1.oap?ck=Search_vr295_-1_1999&keyword=vr295

What did you use for connectors to connect to the regulator?

Sent from my SAMSUNG-SGH-T989 using Tapatalk 2

[smccloud]

Excellent, thank you! I see o`Reilly auto parts has it for $15.

http://www.oreillyauto.com/site/c/detail/MPI0/2VR1.oap?ck=Search_vr295_-1_1999&keyword=vr295

What did you use for connectors to connect to the regulator?

Sent from my SAMSUNG-SGH-T989 using Tapatalk 2

This should work fine http://www.oreillyauto.com/site/c/detail/BWD0/PT173/01539.oap?year=1979&make=Dodge&model=W150&vi=1099863&ck=Search_01539_1099863_2036&pt=01539&ppt=C0189

If you can wait for shipping, going to RockAuto will probably be cheaper.  Just look up a 1979 Dodge W150 with a 5.9 engine.

[Pinhead]

I used the wire end of a spade connector. You can also use a yellow butt connector with the plastic trimmed down.

[smccloud]

Pinhead, where did you find the generic rectifier you used?

[brandEn]

This is a cool idea Pinhead. Can you post some pictures of how you have yours mounted? Other than the cost benefit is there any added benefit of a system like this over a combined R/R combo unit?

[Pinhead]

This is a cool idea Pinhead. Can you post some pictures of how you have yours mounted? Other than the cost benefit is there any added benefit of a system like this over a combined R/R combo unit?

Other than availability and price, the only advantage I can think of is the ability to change the regulator separately from the rectifier if one of them goes bad.

I'll try to get some pics when I get home from work tonight.

[brandEn]

This is a cool idea Pinhead. Can you post some pictures of how you have yours mounted? Other than the cost benefit is there any added benefit of a system like this over a combined R/R combo unit?

Other than availability and price, the only advantage I can think of is the ability to change the regulator separately from the rectifier if one of them goes bad.

I'll try to get some pics when I get home from work tonight.

right on thanks, and thats a good point.

[ABarks]

Pinhead, where did you find the generic rectifier you used?

I am also having trouble finding a source for the rectifier.  Anyone have a good lead?

[Pinhead]

Pinhead, where did you find the generic rectifier you used?

I am also having trouble finding a source for the rectifier.  Anyone have a good lead?

If you use ebay, HERE is a high-current heatsinked rectifier. HERE is the rectifier I am using.

Amazon has many similar options. Google is your friend.

[CycleRanger]

A VR124 regulator will work as well. I don't have wiring color codes yet, though.

Ironically, the color code info for the VR124 is in the very thread you started!
http://forums.sohc4.net/index.php?topic=12465.msg1254662#msg1254662
I installed a VR124 a couple of years ago and posted photos in that thread.


I also installed a separate rectifier (ebay generic 3-phase) based on instructions from that thread as well.

[Pinhead]

A VR124 regulator will work as well. I don't have wiring color codes yet, though.

Ironically, the color code info for the VR124 is in the very thread you started!
http://forums.sohc4.net/index.php?topic=12465.msg1254662#msg1254662
I installed a VR124 a couple of years ago and posted photos in that thread.


I also installed a separate rectifier (ebay generic 3-phase) based on instructions from that thread as well.

That's how I knew that regulator would work.

However, I don't know the color codes of the CB750's wiring harness. If you could tell me what green/white/black is on the CB750 harness I'll draw up a diagram and put it in the original post.

[CycleRanger]

However, I don't know the color codes of the CB750's wiring harness. If you could tell me what green/white/black is on the CB750 harness I'll draw up a diagram and put it in the original post.

Green is ground.
Black is hot.
White is alternator.

Shop manual with wiring diagram available here:
http://www.honda4fun.com/materiale-documentazione-tecnica/shop-manual

I like the VR124 because it's three wire and small.
~$30 and literally plug-n-play.

[scottly]

Doug, the Dodge regulator is better suited as a direct replacement for the SOHC 650 and DOHC bikes, than for the other SOHC bikes. To use this on an 750 or 550, the field wiring needs to be modified, as the stock setup grounds one end of the field coil through the harness, and the reg controls the field current by adjusting the connection to battery +. The Dodge reg controls the field current by adjusting the connection to ground, just like on the 650.
Dave500 suggested a Bosch reg that was pretty much plug-and-play for the older bikes a while back, but it was a bit more expensive than your alternatives. It might be worth the extra bucks for those lacking in electrical expertise?

[Pinhead]

You're right, scottly, I forgot about that.

I'll draw up a diagram for the VR124 that CycleRanger is using for the earlier bikes.

[Masika]

OK so i got the dodge regulator and a 3 phase rectifier and i understand where all the wires go except 2 of them. both of the solid blacks. 1 that comes from the rotor that runs with the 3 yellows and a white one AND the black that runs with a red/white and a green wire to the OEM regulator.

[jpfrk2001]

Just posting to help me find this at a later date. Awsome tech!!

[SchoolDaGeek]

Masika, if all your connections are correct, the two black wires are simply jumped together.

[Masika]

OK so asking a question i had a week ago and never got a response in another section. can a bad battery cause over voltage. or maybe something else that is going soon OTHER than the R/R. OEM R/R gave me over 15v at 3k. used R/R from ebay over 15v at 3k. tired of messing with OEM so tried this MOD. followed instruction to the par and i get same results. 13.5 at idle and over 15 even 16 at 3k RPM's. which could mean i had a good R/R to begin with and didnt need to spend an extra $50.    Please someone help me answer this as you can not return a $60 battery after adding the acid.

going to post video in a sec.

79' cb650 over voltage