Charger Fault Diagnosis Help Please

 

I have a very nice little commuter, a HONDA CG125BR. Great little bike
saves me loads of money as it will run for ever on one tank.

Used it for the first time at night, a few weeks ago, and found that the
Indicators either didn't work or flashed very slow, until I really
revved the engine. Charged the battery as it was a little low, and all
was great.

After a couple of days it had the same fault.

Did some testing and found that with the lights off all works OK, and
the battery starts with a voltage of about 10v, ok low, but then there
is a problem, and when it is started, and the revs get high enough, the
voltage goes to around 14v. From this I am guessing the charger works.

But even with the engine running quite high, if the lights are put on
the voltage drops to around 9-10v.

Shouldn't the charger keep this up to 13v + to allow charging?

If yes can I say for certain that changing the Stator for a new one will
cure the problem, or is there a way of testing the Voltage regulator, as
friends have said this too could be the problem?

Sorry for the lengthy explanation but hoping that someone can help with
all this info, as I have to use this for work, and the days are drawing
in making the use of lights a must.

Thanks in advance for any help offered.

Chanon

 

Chanon wrote:

 > I have a very nice little commuter, a HONDA CG125BR. Great little
bike saves me loads of money as it will run for ever on one tank.
 >
 > Used it for the first time at night, a few weeks ago, and found that
the Indicators either didn't work or flashed very slow, until I really
revved the engine. Charged the battery as it was a little low, and all
was great.
 >
 > After a couple of days it had the same fault.
 >
 > Did some testing and found that with the lights off all works OK, and
the battery starts with a voltage of about 10v, ok low, but then there
is a problem, and when it is started, and the revs get high enough, the
voltage goes to around 14v. From this I am guessing the charger works.
 >
 > But even with the engine running quite high, if the lights are put on
the voltage drops to around 9-10v.
 >
 > Shouldn't the charger keep this up to 13v + to allow charging?
 >
 > If yes can I say for certain that changing the Stator for a new one
will cure the problem, or is there a way of testing the Voltage
regulator, as friends have said this too could be the problem?
 >
 > Sorry for the lengthy explanation but hoping that someone can help
with all this info, as I have to use this for work, and the days are
drawing in making the use of lights a must.
 >
 > Thanks in advance for any help offered.
 >
 > Chanon
 >

A little more to add.

I took the bike for a good run, 30min or so averaging a speed of about
55MPH. After a little over 4 hours the battery had some 12.3v in it. On
starting the engine, which I should have said is Kick start only, it
again hovered around the 13.5-14volt.

Now when the lights are put on, and your doing around 1500-2000 rpm,
guessing this as no meter, the voltage it around 11.5-12v.

Am I still correct in thinking that this voltage should be more like
113.5-14v to ensure a good rate of charge?

Again many thanks for any help  you are able to offer.

Chanon

 



This is normal behavior. Your alternator is working.


That is correct.


Don't change the expensive stuff until you've done all the basic stupid
stuff first.


Oh, no, the info you gave is quite good and characterizes the problem
pretty well. It's much better than the "my bike won't start" post that
got me into QA Manager Mode the other day. :-)


Yes, it should. (13.5 is good.)


Here's what I recommend: Check and clean every big electrical
connection. First remove the ground connection on the battery, then the
hot. Clean every connection with some fine sandpaper or a wire brush.
There will be a lot of crud on the mating surfaces. Just do the major
fat wires, both ends each. When you hook up the battery again, do hot
first, then ground. (That's just a safety thing. If you undo hot first
or reconnect it last then the back end of the wrench could hit something
ground and surprise you.) There's a good chance that just cleaning all
the major electrical contacts will solve a lot of weird behavior.

While you're at it, if the battery has ports for checking the
electrolyte level, open them up and have a look. Clean the top off
first, then open one port at a time. Each should have a kind of finger
that pokes down into the water: that tells you the correct level. If
it's low, add distilled water. (Not mineral water, not clear spring
water. Distilled water.)



Timberwoof <me at timberwoof dot com>
faq:  http://www.timberwoof.com/motorcycle/faq.shtml

 

This is worth checking into all well if you are going to
go to the trouble of cleaning all the contacts, protect them from further
corrosion.
This stuff works.

http://store.caig.com/s.nl/sc.2/category.822/.f