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charging system

Posted: Thu Aug 17, 2017 3:46 pm
by lwellis
I have replace the rotor, stator and rectifier, still not charging battery. Continuity on stator and rotor is good. Cannot get any AC voltage out of stator at 5000 RPM. I have tried 2 new stators and 2 new rotors, still nothing. I replace the brushes when I first replaced the stator. Don't know where to turn.

Re: charging system

Posted: Fri Aug 18, 2017 10:32 am
by GeorgeSweety
Hi Iwellis, I can't help you myself as I'm not very good with electrickery but have a read of this, if it doesn't help then try the forum search box at the top right.
viewtopic.php?f=4&t=13337&hilit=stator+not+charging&start=15

Re: charging system

Posted: Fri Aug 18, 2017 10:34 am
by GeorgeSweety
Ooops! link is for page 2, you may want to read from page 1 :oops:

Re: charging system

Posted: Fri Aug 18, 2017 2:19 pm
by MEHall
Well my CB 650 would not charge and i changed both rotor and regulator and still it would'nt charge, at the end i was forced to replace the electrical harness and after that no more charging problem. :wink:

So by the means check up if you got a faulty electrical harness. :wink:






8)

Re: charging system

Posted: Sun Aug 20, 2017 12:10 pm
by tario
You could just run some new wires to replace the yellow ones. I didn't notice the year in your post but generally the stator puts out 3 AC signals on 3 yellow wires. IIRC you need silicone jacket wires and stake-ons/crimp on connectors to make the connections to the current devices(soldering isn't a bad option either, and using shrink tube and/or splicing tape). There is wire rated to be out in the sun. I'm not sure if bikes have sun rated wiring but I'd try to put that in. If there is a cheap harness locally and you are diligent with the swap it should be a bit easier though.

Re: charging system

Posted: Sun Sep 17, 2017 8:35 pm
by lwellis
I really appreciate all the help, because I am about lost with this issue. Like I said before, I have used 2 different (new) stators, 2 different (new) rotors, 2 different (new) rectifiers, 2 different (new) batteries and replaced the brushes. I have checked the continuity on the rotor and stator, all good. From what I have read, I should be getting 50 or so AC volts through the 3 yellow leads coming from the stator at 5000 RPMs. I'm not getting shit. It's just a rotor spinning inside the stator, connected by the brushes. They are all new yet I am not getting anything out of the stator. Could this be a ground issue? I have also read a lot about the main wiring harness issues. I am prepared to change the wiring harness, but I would like to be reasonably certain this would correct the issue. Even though when testing the stator, straight off of the stator wiring harness, and getting basically no AC voltage, could it still be the main wiring harness? I mean, testing that way doesn't use the main wiring harness at all. That's why I am wondering if it could be a ground issue being caused by the main wiring harness.

Re: charging system

Posted: Mon Sep 18, 2017 1:57 pm
by lwellis
I did some further testing. It is my understanding about how this charging system works, that 12V DC is sent to the rotor to generate the AC voltage coming out of the stator. From what I can tell, there is almost 12V DC coming out of the rectifier (checking voltage on the black and white wires where the rectifier connects to the stator). If I am not correct in my thinking about how this charging system works, please set me straight. Does it make any difference which wire is connected to which brush? Just don't really know where to go from here. My thinking is, if I am getting the DC current out of the rectifier to go to the brushes then the problem is not in the main wiring harness.

Re: charging system

Posted: Tue Sep 19, 2017 5:32 am
by Folsoml
Here is a link to a trouble shooting guide for the charging system. It was written for the DOHC Honda models of the same era, but the system on your bike is basically the same.

http://www.cb750c.com/publicdocs/chargi ... ystem.html

I hope the helps you.

Re: charging system

Posted: Sat Sep 23, 2017 1:44 pm
by lwellis
Well I used the troubleshooting guide and have the test results. Don't have a clue how to read the results. Any ideas?

1a. System VDC - @ motor off, key on _______________12.2

1b. System VDC - @ idle __________________________12.2

1c. System VDC - @ 3000RPM ______________________ 12.2

1d. System VDC - @ 5000RPM ______________________ 12.2

1e. System VDC Bypassed @ 3000 RPM _______________ 12.2

2. Magnetism? ____________________________________

3a. Rotor VDC @ motor off, key on __________________ 11.5

3b. Rotor VDC @ idle _____________________________11.4

3c. Rotor VDC @3000 RPM _________________________11.5

3d. Rotor VDC @ idle regulator bypassed______________11.2

3e. Rotor VDC @ 3000RPM regulator bypassed ________ 11.3

4. Stator VAC ____________________________________0

5. Rectifier out VDC ______________________________12.0

6. Regulator Black wire VDC _______________________11.5

7. Regulator Ground wire VDC _____________________0

8. Rectifier wire Voltage drop VDC _________________.1

9. Charging Amps DC ____________________________-5.7 @3000 RPM 6.1

Additional Information: __________________________

All connections look good. New rotor, stator, brushes, rectifier, battery. Will not charge battery.

Re: charging system

Posted: Sat Sep 23, 2017 3:54 pm
by Folsoml
Yep. That's definitely not good. You should be getting around 14 volts or so at 3000 rpms. At what point did you change your rectifier? A bad rotor can burn out a new rectifier pretty quickly.

Re: charging system

Posted: Mon Sep 25, 2017 4:59 pm
by lwellis
I replaced all 3 components (stator, rotor, rectifier) at the same time. All new parts.

Re: charging system

Posted: Tue Oct 03, 2017 10:09 am
by lwellis
I checked the voltage at the brushes. I am getting 12 VDC to the brushes. I can tell that the brushes are making good contact with the rotor.So can anyone tell me why I am getting 0 VAC out of the stator? Again, rotor, stator, and rectifier are all new.

Re: charging system

Posted: Tue Oct 03, 2017 7:29 pm
by Folsoml
I wish I could help. By your description, you should be charging. Have you gone through all the electrical connections in your wiring harness and cleaned them? Checked for continuity in all your wires? Made sure all your grounds are...grounded?