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My Honda CB 500 -73 has some problems. I bought the bike non running and it had been sitting for some years.
Now when i fired it up i noticed that I have absolute no power out from the stator. I checked the Ohm resistance between the three cables and it says 1.2 ohm.
I removed the stator and the cables and everything looks ok.
Do you have your meter set to a/c volts in the correct range? Another way to check the charging system if you are unsure of your result from an a/c output test ( check at min. 3k rpm) is to test the battery DC volts key off unloaded then start the bike and check the battery DC volts at idle. If there is no significant change or there is a voltage drop, it could be any one of or a combination of charging system components. If it does raise the voltage at the battery when running at idle, your charging system is probably OK.
And for both tests I assume you checked lead to lead in every configuration.. at what rpm did you do the test? What is the factory spec for the resistance test?
Also you said that when you fired it up you 'noticed' that the stator wasn't putting out any power. How did you 'notice' this? Or what was it that prompted you to test the stator?
OK good work. I am not the most familiar with the cb500 charging system and hopefully an old hat at these will have some input soon but, does it by chance also have a field coil for that year?
I have a bit of a quirk that some techs don't. I trust my electrical tests. When it says no bueno, es no bueno. Battery not charging, no power from the stator despite a decent ohm reading. If one test is bad, the component is bad. If you trust your tests.
If there is a field coil, it will likely be a resistance test between a white wire and a ground. You would see around 4-8 ohms on a good one, if you have one.
On my CB750 the alternator connector has 5 wires, 3 yellow a white and a black. As Dohc mentions the white and black would be the field coil, if that isn't powered the coils won't generate power.
Does your connector have 5+ wires?
If it does..
- When you tested the yellows did you have the entire connector disconnected?
- When everything is connected and the bike is on are you getting voltage on these wires?
I guess my totally home made wire harness has a little more to wish for
Today i put one cable from + to the white cable, and one from - to the green so I would be sure the field coil got power. Then I got 40-50 volt from the yellow wires. Right after that i got som other stuff to do so I have not done any more testing. But I believe i have to take a look at my wireing.
The reg/rec i have is a cheep one from China. Three yellow, one red, one green, one white cable.
I had it connected like this, yellow to yellow, red to red, white to white, green to green and ground.
Thanks a lot for all the help! Please reply if you guys have some more ideas.
Ok then, good progress. I think with proper wiring and continued inspection and repair, you will be on your way.
If you dont have confidence in your wiring abilities there is no shame in having an electrical specialist make you a harness. If you decide to do it yourself, really take your time and do your absolute best with every aspect of the project. Never half ass your wiring.
Ok never half ass anything actually. Especially not the wiring.
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