Problems with charging system HELP!!!!

Ok guys, I need your help again. The problem I am having is with my charging system, I can fully charge the battery, start the bike up and let it idle for 30 min and the battery close to being dead well at least enough that it won't turn the bike over again. I have tried starting the bike and then see if it would run without the battery being connected while it's running. I also tried changing out my regulator/rectifier and still the same results. I was wondering if I would have to change out the generator rotor or the stator. Oh yeah the bike will run for about 10 seconds after I pull the battery but when I pull the battery it runs like a car does when your alternator is going out and your battery is almost dead but when the battery is hooked up it runs great. Any help would be appreciated thanks guys.

 

I wont tell you that there are several good threads on this very subject, as that would mean I have to provide a link.

you will need a good multi-meter and know how to ue it.

the idea: your "generator" is a three-phase altenator. the regulator/rectifier is actually a diode bridge to turn this ac voltage into dc and a small circuit to drop the excess voltage to the frame(ground)

the process: take your sides off. on the left side you will find a group of wires comming out of the engine where the altenator is. seperate this connector. using your multimeter on resistance (ohms, the figure that looks like a horseshoe) measure and record the resistance of each coil. a-b, b-c, c-a, a-g, b-g, c-g (g=frame or batt neg, they should be about 20ohms between the coils, and infanite to the frame). if you have any coil that goes to frame then the stator is grounded, if you have any coil that is not with in 10% but less than twice of the others you have a shorted coil, if you have no reading or a reading that is equal to the other two coils resistances added together then you have a break. any of these means the stator is bad.

next test if nothing is found wrong with the stator: (caution: this will be testing live and deadly voltage/current levels, DO NOT TOUCH WITH BARE HANDS) leave the altenator unplugged, charge the battery, then start the bike(you can use the bat-charger to keep the bike running by reconnecting it after the bike is started.)
use your multi-meter in ac-200v, and pick one pin to be the reference and conncet a probe to it, then touch the other probe to each other pin and record the voltages. this should be done at 5krpm as that is the charging/cruising speed. the voltages will vary on rpm and between each coil. a test to frame from each coil will verify that there is not an intermitant ground to frame. An average voltage at idle should be about 20-40vac but this will be different on each rotor/stator combo. @ 5krpm you should see about 60vac or more, but no less than 30vac. again these are not hard figures, they are just for reference.
If you do not see any voltage then you will have to dissassemble the altenator and see if the rotor spins with the engine or if there are any arcing marks on the casing of the stator. if this all fails you may need a new rotor as they can (under certian circumstances) loose their magnetism. but that takes quite a bit to do. If you get good voltages at the altenator then stop the enginge and reconnect the altenator and then disconnect the regulator/rectifier and test the resistances and then voltages you get here. caution two wires are directly connected to the batt positive and one to frame. this is intentional. if any of the wires from the altenator show no resistance or conenuity to frame then replace that section of the harness as there will be damage to the other wires.

happy hunting

 

hey tink, didnt see your post, I just paraphrased the backshop manual, please pointout any of the mistakes

Zen

 

if only correct spelling fixed bikes!

 

Wow that is probably the most detailed information I have ever received on this site. I really appreciate y'alls help maybe I can finally be able to ride this summer especially after 2 years of rebuilding this bike I am so ready to ride it. Hey rink may I ask why it is bad to disconnect the battery while running and how does it ruin a rr

 

Oh ok well that makes sense. I will remember that and never do that again thanks for the info. Once I get the problem figured out all I have to do is a little bit of body work and then paint and it should be ready to go. I just can't believe I am almost done with the bike, hurray!!

 

The regulator in theory should take any excess voltage above 14.5V that is going back to charge the battery to ground as long as it is working properly.

 

I had this same problem just last week. It turned out to be the starter solenoid. I stongly reccomend using only the original solenoid (found easily on Ebay) I used an aftermarket one and fried my wire harness. Cost me 100$ plus 4 hours to install the new harness but the bike runs great now. I would check the solenoid before going through those tests, they take a lot of time and like I said, my problem was exactly as you described. Good luck!

 

Don't expect your battery to charge while the bike is idling cuz at idle speed the battery is discharging slowly. With lighting and ignition loads, not enough power is being generated to add to battery charge until rpms rise.

 

What was wrong with the solenoid and how did you know it was bad.

 

It was fried. After a week of trial and error I figured it out. Eventually the relay on the solenoid went and I lost all my power on the bike. So I jumped the starter to the battery. That's how I knew it was the solenoid. My battery and starter were still good.