Charging issue and what to check

[dbyers]

I have a 1979 XS100SF with an on-going charging issue. It seems that the battery will not charge. This was an issue when I bought the bike a year ago. The battey is new and all wires seem to be connected correctly with no exposed broken wires. I hate to say this but I did buy an Ohm meter but I'm not sure what to check or what to set the meter on to check it. I do have a complete stator assy with cover that I bought off of e-bay. I'd rather confirm the stator was the issue before tearing into the motor to replace it. Can anyone get me on the right track?

Thanks,
David

[randy]

David,

Do a search here for posts. There are a lot of post concerning charging problems. And, if you have a copy of Clymers' repair manual, there is a good troubleshooting section for the charging system from the stator & field coils to the rectifier.

HTH

randy

[scoobes]

i had a charging system problem on my e model,the battery was not charging and my rev counter was not reading correctly,i put a different rectifier+regulator ass on and then it was ok.

[John]

Replacing the stator is a easy job. Just unbolt it from the right side of the engine, unplug the wires behind the fuse panel, and bolt the new one up. No engine disassembly required. Did you get just the windings, or did you get the entire assembly including the engine cover?

[dbyers]

John,
I was able to get the whole thing including the engine cover. I guess my main question that I need to find out is how is the best way to test it to rule it out as a problem? I'm hoping to take the weekend and devote it to using some of the suggestions I've seen on here and in some of the other Forums.
Thanks for all the help....

[randy]

OK, Dbyers,

Stators RARELY go bad. They are constructed of very heavy guage wire.

The FIELD coil can be tested with a thin feeler guage or paper clip.

Hold the feeler guage (paper clip) about 1/4" from the cover and turn on the ignition key. A good field coil will pull the feeler guage.

This test will prove that power is getting to your field coil. Next place to check is the field / stator connectors. They're located behind the fuse panel. You'll have to remove the fuse panel to get to them. Corrosion on these connectors is a common problem.

Remember, if your tach is working, then the stator is putting out juice and most likely the trouble is the rectifier / regulator assembly.

Have fun

Randy

[dbyers]

Randy,
Thanks for all the help. I did the paper clip test and the clip was pulled right out my hand and the tach is working properly. So I'll try the other tests when I get home.

Thanks again,
David

[sixtysix]

David,

I have only seen one or two Stators go bad in my XSperience, and one was going by hearsay from a 'questionable' mechanic. So chances are it is the reg/rect unit or bad battery/connections.

First thing you need to do is make sure you have a good battery, no other tests will work unless the battery is good and fully charged. Make sure battery cables and connections are clean and tight, including the frame ground. Make sure fuse box connections are good. Check all other charging system connections (with battery disconnected please) are clean and free of corrosion. All that done? Now you can determine if there is a problem and what it is.

I think the book asks you to check the voltage across the battery with the bike running, at different RPMs. It should increase from 12.0 (approx) to 14.5 +/- .3V (set my throttle lock at 2000 RPM ) if you do you may have a problem with something drawing too much power (got aux lights or something?) If not either rect/reg is bad or Stator...I think the stator is a simple resistance check, if you have no opens or shorts it is OK. If is OK then the regulator is most likely bad...since it had diodes it is most likely to fail. Is your tach working? If not for sure it is the reg/rect unit.

Here is some car info but alot of it is the same How it works

Check this link too...
My battery won't stay chared!

Great thread right here at XS11.com http://www.xs11.com/forum/showthread...&threadid=4206

Good Luck! Let us know what you find.

[dbyers]

Well I FINALLY checked the Volts across that battery with the bike at idle. At idle I got 12.3 Volts and when I pushed the tach up to 5000 RPM I only got 12.53 on the multimeter. This is my first dealing with eletrical issues but from what I can find I'm afraid it's the stator. I found a few more tests that I'm going to do tomorrow to try and confirm. Thanks again for all the help.

[mixelpix]

Thanks!!

Randy & 66 - I am also checking out charging and ignition systems - lotta mystery wiring from the PO. I have yet to troll the archives re: these issues and just wanted to say thanks for the practical tests info!
-Patrick Kennedy

[randy]

David,

Go back and re-read the above posts. You might have skipped something.

If your tach is working, and your headlight and dash lights come on when the engine fires up, your stator and field are working.

If your connections for the field and stator ( located under the fuse mounting bracket) are clean and tight, next clean and tighten the connectors at the reg/rectifier. Don't miss the ground connector on the reg/rectifier.

Do all of this and, if you still have this problem, change the reg/rectifier.

And have no fear, after a year or so of XS electrical troubleshooting, you will become an XS elec. GURU!

(like we have a choice!?)

Randy

[skids]

Along with what Gary Granger and others have told you, you might just try another rectifier/regulator unit that is known to be good. Those things are difficult to test because it takes a given minimum amout of current to close the diodes. Some multimeters do not make the cut with their itty-bitty batteries...at least that has been my experience. I got different results with different testers. Do clean-up the connectors as was suggested, and don't forget the negative strap's frame mount. There is also a strap from the engine to the frame that you might clean, just for completeness.