Charging issue! Help please

[mike the bike]

Must be with a name like Nippon Denso.

[Wenman]

The three phases go through the full wave rectifier so it won't make any difference - trust me.  It might be an idea to check the ac voltage on each of the yellows.  I don't know what the actual voltages are without measuring them but all three phases should read roughly the same.  If there's nothing coming out of the alternator,  the next thing to check is if there's 12V across the exciter coil (the one in the middle).  Without a magnetic field from the exciter coil you ain't gonna get juice in the yellow wires.

There's a little man inside the regulator with a volt meter measuring the battery.   If it's too low he thinks "ay up,  getting a bit low here, best get the alternator going"  so he flicks a little switch and makes the exciter coil get excited,  hence the alternator gets making juice.
If the little man measures it too high he has to turn the exciter coil off or the battery will blow up and the little man will get a bollocking.

Hope this helps.

Thanks again,

Can u explain in laymans terms.. testing the ac current across the three yellows is that done engine running on not?
Also where how do I check the 12v on the exciter coil?

Wish that little man would start doing his job properly or I'm giving him the boot!!

Oh also.. if I disconnect the stator block from the harness and test the three yellows coming from the stator (yellow to yellow all combinations) I get correct readings.. if I put the black probe on the frame and the red probe on each yellow wire I get nothing whatsoever! Does this mean it's shorting somewhere??

Al

[petermigreen]

The three phases go through the full wave rectifier so it won't make any difference - trust me.  It might be an idea to check the ac voltage on each of the yellows.  I don't know what the actual voltages are without measuring them but all three phases should read roughly the same.  If there's nothing coming out of the alternator,  the next thing to check is if there's 12V across the exciter coil (the one in the middle).  Without a magnetic field from the exciter coil you ain't gonna get juice in the yellow wires.

There's a little man inside the regulator with a volt meter measuring the battery.   If it's too low he thinks "ay up,  getting a bit low here, best get the alternator going"  so he flicks a little switch and makes the exciter coil get excited,  hence the alternator gets making juice.
If the little man measures it too high he has to turn the exciter coil off or the battery will blow up and the little man will get a bollocking.

Hope this helps.

Thanks again,

Can u explain in laymans terms.. testing the ac current across the three yellows is that done engine running on not?
Also where how do I check the 12v on the exciter coil?

Wish that little man would start doing his job properly or I'm giving him the boot!!

Oh also.. if I disconnect the stator block from the harness and test the three yellows coming from the stator (yellow to yellow all combinations) I get correct readings.. if I put the black probe on the frame and the red probe on each yellow wire I get nothing whatsoever! Does this mean it's shorting somewhere??

Al

When you say nothing whatsoever, do you mean '0.00' or another symbol.
0.00 means zero ohms as in no resistance, not good. If it's another symbol (depending on the model of your meter) could be an up arrow or OR (over range) or something else it means infinity resistance which is good.

You need to conduct the ac voltage test with the engine running or you won't see anything. Remember it's an ac voltage test (it hasn't reached the rectifier yet) so select AC voltage range on your meter.

Have you got a wiring diagram for your model? There should be a 12V feed to the exciter. You need to identify it and test across it and negative/frame/earth.

Check out this video. It's for a car but valid and may help. https://www.youtube.com/watch?v=VYkTdnwQKJ4

[mike the bike]

Reading a high (infinity) resistance between the yellows and ground is correct, otherwise all your newly minted ac will disappear and not get rectified.
IIRC there's a plug with the 3 yellows, a light green/red (neutral light) and blue/red (oil pressure),  a green and a white.  It's the green and white that should have 12V across them. 
All checks to be made with the engine running, it won't charge if the alternator isn't whizzing around.

[Wenman]

Just got out of bed and tested it again in my boxers!!😂

My meter reads  |  . 
So as it's not 0.00 I assume that funny symbol means infinity or similar?
Shame thought I may have discovered the issue!

I'm inclined to re wire the entire bike with a motogadget m unit as I'm sure it's a wiring fault on my behalf and it seems too difficult for my skill set😩
It seems the stator coils are all testing fine, it's a brand new idiot proof rec/reg so components are all good but something's still ruining my day everyday!!

[petermigreen]

Where are you in the country?

[Wenman]

South west! Torquay to be exact!! I'll pay ur travel if u want to come and have a go peter! 😬

[petermigreen]

I will be in Devon sometime this summer...

[Wenman]

Excellent keep me posted as now doubt I will still be trying to resolve this next summer! Kettles always on!!

[mike the bike]

I'm on call next weekend,  if I'm in Torquay I'll call in and get paid double time for sorting your bike out.

[Wenman]

If u can sort it out I'll pay you triple time and throw in some beers!!

[Bryanj]

To help understand the charging system try reading the link below

http://manuals.sohc4.net/general/motorcycle_electrics/HondaMES3.pdf

[Wenman]

update...

So last night I went through all the back end harness checking all the wires had continuity.
I have checked the white wire from rec/reg to stator, correct, the black wire is def getting ignition live.

I have now exhausted all tests and still cannot come up with  a resolution.

In a last ditch attempt I have ordered another inner coil and feild coil to replace what I have. Although they test fine I am hoping they are failing when in operation.

Im feeling very beaten by this now... :-(

[petermigreen]

Has it been like this since rebuild? I'm wondering if the windings have become de-magnetised whilst laying dormant.
Don't give up. Once you've solved it you'll feel great.

[Wenman]

Thanks peter,

I only did a top end rebuild so didn't touch the alternator other than inspection and clean up!
The one thing I did notice is on completion of the build is I had a high pitch metal on metal scrapping noise from inside the stator cover, almost like the rota was slightly off set. On inspection I can see where the rotor has fouled on the inner coil. Could this have demagnetised it?
I had ridden it for a while with the noise like that until I got the chance to remove it and refit it since then no noise. Sadly I cannot connect the time of the noise to the charging issue. What I can say is since completion of the build I have ridden the bike 4 times no more than 4 times each for no more than 12-15 miles! Two of which required me pushing the thing home!

Sad times