RR38 Regulator Rectifier - Where to buy

[bcware]

True enough; it will help some people and hinder others, but advanced builders probably won't be scared of chopping it up. A total newbie might be scared of the job, however.

You could poll all of the options.

Cheaper + no connector
More expensive + connector
Etc

If it is possible you could make them to order perhaps? Not sure how this would work for you logistically.

 

[DanD]

I got the rectifier and heat sink from China via Amazon for $8, the regulator locally for about 20.

As promised, here is the install pics using Leo's rectifier and regulator combo. The heat sink had the same thread as the mounting bolt from the old rectifier (go figure). I bent the original mount straight down so the rectifier sits sideways and will then fit above the tool compartment in the XS360. The wiring is just for testing at the moment, I would organize the wires a bit better and heat wrap it for a more permanent install. I did have to route the rectifier wire around the front instead of the back (pic shows back), because the wires are too short the way I have attached it.

I checked the resistances on the rectifier. One way everything is stopped, so the diodes are working. The other way B-->R is 3.34 MOhm, B--W1 is 2.41 MOhm, B-->W2 is 2.96 MOhm, B-->W3 is 3.49 MOhm. So I figure all is good enough to work.

After install the new reg and rec, things work well, my headlight relay click and voltage leak on connecting the battery has stopped (why I started my other thread, and jumped to this one to source a new rectifier), but still no charge. I will continue with this on my other thread on this. The main point here is the reg and rec work well so far, are reasonably cheap, and can be mounted in a similar to stock posiiton.

 

[DanD]

The #24-2089 is set up for the early XS650's. That reg/rec controls current flow through the field coil by sending current to the field coil then to ground.
The later, 80 up controlled the current flow by grounding the field coil. The field coil got current right from the brown wire.
To use that reg/rec you would hook it up as in these directions I'll post up.
The field coil hooks up with a similar color code. If not Just hook the orange wire to one wire for the field coil, the other wire of the field coil to ground.
Leo

Hi XSLeo, sorry to bother you, but I'm reviving this thread from last year. I got my bike running, but not charging. I have gone through things again this spring and find that it is probably the new voltage regulator that is not working.

All my ohms are in spec for the field coil and the alternator. Nothing grounds out. I get a magnetic pull on the field coil to a wrench when I bypass the voltage regulator with the key on. But "nothing" (80 mV) out of the green wire on the voltage regulator when I am running at 3000 rpm and the battery is slowly discharging (to a low of about 12.2 volts before I turned it off). There is power from the brown wire to the voltage regulator. It is grounded well (I ran an extra ground wire from the frame ground to the black wire in the harness).

I had swapped in a VR733 (it was supposed to be a VR295, but it cross-referenced to a VR125, and a VR733 by Victory Lap which is the one they had in stock for $20.).

Do you know of any reason this thing would not work on this bike? Does it just appear faulty? Is there any other way to check it?

 

[Wolfe_11B]

Something isn't wired correctly.
Remember that the XS360 harness and wiring is different than that of most xs400's (from what I've seen in the diagrams).
When you are testing the field coil while bypassing the regulator, how are you doing that? Just feeding battery voltage to one wire?
When you have it running and you check the green wire output(that's giving you nothing), how are you doing that?

With that voltage regulator, if you are using the stock xs360 harness, you need to eliminate the ground wire from your field coil and run it direct to the regulator. The stock harness grounds one side of your field coil permanently and the regulator deals with it differently (I think stock had a mechanical regulator?).

I guess what we need to know is what you did to the wiring, if anything, when hooking up the new stuff. If you just left it stock and spliced into the new regulator and rectifier, things will be wrong.

 

[Wolfe_11B]

Maybe this will help you understand whats going on. Basically you need to change from the diagram on the left, to the diagram on the right, if you want that regulator to work.

 

[DanD]

OH. So that means the brown wire (from the harness/fuse) has to connect to the black wire (from the field coil) before they both connect to the pin on the regulator. If that is the case, I can just jumper them across from the pigtail connection, and remove the black wire from the pigtail, and ground the case separately.

I was grounding the black wire like the original picture on the left. I wonder if the black wire grounds anywhere else, like near the coil? From your diagram, it looks like it... but there is that black wire that runs wire back from the field coil. I will check it all for continuity tomorrow.

Yes, the stock regulator is a mechanical one. It is labeled "NiponDenso" and says"026000-2790" on one line, and "12V 2P" on another line. It has two pins on the back, that go to the green and brown wires on the harness, and the solid black that comes from the field coil goes to the case and ground.

So there must be a fundamental difference in the way the two regulators adjust the voltage with ground...?

How was I checking things?

• I tested the field coil just by running a hot wire from the positive terminal to the green wire of the field coil (with the v. regulator unattached). Then I put a wrench near the field coil and it stuck to the crankcase.
  
• When it was running I was checking (with a voltmeter) the green wire out across to the negative on the battery. Everything was hooked up, I was just checking from the connection where the pigtail connects to the wire harness. The wrench wouldn't stick.
  
• I watched the voltage drop just by checking across the battery terminals as the bike was running.

If I disconnect the regulator, can I jump a hot wire to the green field coil wire while it is running, just to see if it will excite the coil and charge?

Thanks for your information and help!

 

[Wolfe_11B]

OH. So that means the brown wire (from the harness/fuse) has to connect to the black wire (from the field coil) before they both connect to the pin on the regulator. If that is the case, I can just jumper them across from the pigtail connection, and remove the black wire from the pigtail, and ground the case separately.

You are on the right track!

I was grounding the black wire like the original picture on the left. I wonder if the black wire grounds anywhere else, like near the coil? From your diagram, it looks like it... but there is that black wire that runs wire back from the field coil. I will check it all for continuity tomorrow.

Yep, that's the key. Gotta make sure that the field coil isn't going to ground anymore. Ground the regulator case, and let the regulator worry about sending the field coil to ground. Easy peasy!

If I disconnect the regulator, can I jump a hot wire to the green field coil wire while it is running, just to see if it will excite the coil and charge?

I would refrain from doing this, since without a regulator it could feed the full DC voltage that the stator is capable of very quickly. The regulator can cut it on and off faster than you can

 

[DanD]

OK, I should be able to try this tomorrow.

But with this setup... there is 12V on the black wire, whereas before it was ground... does this "backward voltage" affect the field coil at all?

 

[Wolfe_11B]

Just make sure one side of the field coil is connected to 12v and that same line branches off to the input on the field coil. The other input on the regulator goes to the other side of the field coil, and should be connected to nothing else. Regulator case gets grounded.

I don't know the colors in your harness, so I'm afraid to comment on what I think is what You just have to check for continuity, and double check.

 

[DanD]

Thanks! What you said makes sense. I'm sure I know the colours.

 

[Wolfe_11B]

This shows pretty much what I drew above, just with your regulator.

 

[DanD]

Yeah, that is right. I saw that pic on a car site when I was trying to figure things out.
It is the same regulator as mine, same connector, same shape and everything.

Thanks again. I will try it out tomorrow.

 

[DanD]

OH! I see what is happening. In the original XS360 setup, with the mechanical regulator (VR), the VR "pushes" power down the green wire through the coil to the ground (completing the circuit). In the new setup, the VR "grounds" to complete the circuit "pulling" power through the field coil. Ha! I think I've learned something. Thanks!

 

[Wolfe_11B]

Yep, the regulator is simply a fast switch with a sensing circuit, that switch can either be on the hot(12v) side or cold(ground) side.

 

[DanD]

It worked!

I just bypassed the black wire that goes into the harness, because it was grounded somewhere in the wire harness (I started to look for it, but it was just too far in).
So I connected the black wire from the field coil pigtail to the brown wire* in the regulator pigtail. Then I made sure the regulator case was grounded properly.

When I rev up the engine it goes up to 14.5 volts at the battery, and stays there.

So this setup works! (the $8 rectifier wired in as I show up above, and the $20 VR733 regulator (I am in Canada, these things are a bit more expensive)).

*The brown wire is brown on the harness, but it is black with red stripe on the original regulator pigtail, so I usually call it the brown wire, even though it is different in the pics.

Thanks VERY MUCH for the good advice!

 

[arfstrom]

Glad it worked, I have a question? did you use a pigtail on the VR? or did you come up with something?
http://www.oreillyauto.com/site/c/detail/BWD0/PT173.oap?ck=Search_pt173_-1_-1&keyword=pt173
I paid about 10 bucks for this? I thought it worked well.

 

[DanD]

I just used the crimp on style bullet connectors that I connected to the end of the original pigtail I cut off of the mechanical regulator. That way I still had the connection to the harness intact. I cut the plastic back on the face and gave them a little squeeze and they fit like they were made for it. If you look back in this thread, all my wiring to the individual parts is in there. The rectifier is still all open. I will need to adjust it a bit to make it more water/dirt/dust proof in future. Your idea may be a good way to go with the regulator.

 

[arfstrom]

This was my adventure into getting a new VR/rec...
charging sys.

maybe not the best pics, I took a HP computer case to make a holder, and put it behind the batter, under the fuse box.

 

[Wolfe_11B]

Glad it works bud! That is the issue most people have when switching to aftermarket electrical parts. They have a good grasp on what should be attached where, and they can read the wiring diagram, but most never bother to dig into the harness and find what actually terminates where, and what branches out to other places. It's not always laid out in the harness exactly as it's drawn in the diagram.

That VR will probably last forever, its built to handle loads from vehicle charging systems (hence the size of it).