Charging problem

[msbuck]

AARGH!!!!
OK, now that I've got that out of my system...

When I took the Precision Maneuvering Class, all that slow riding with my lights on took it's toll.  Of course, by noon my bike quit starting on it's own.   I remembered that I should have disconnected the headlight, etc.  Graham took care of that for me when we took our lunch break, but we still had to bump start the bike every time out.  

We checked the charging system after we got it back home.  The generator light was being very sporadic.  
1.) Switch on, light off, hit starter, light came on, would go off around 1200rpm.  
2.) Switch on, light on, engine running, light would not go off.
3.) Switch on, light on, engine running, light would go off around 2500rpm.

We checked the charging and had only about 12.8 volts charging maximum.  We checked the brushes.  They were worn, so we replaced them. Now, I have never soldered anything before and this was not a pretty job (to say the least!).  But we got everything put back together and checked things out again.

NOW the Gen light comes on very brightly and STAYS ON.  Sigh...
Checked the charging and we get NO charging, just the same voltage consistently throughout the rev range.

We checked the rotor and got a good reading.  We're just stumped because before we replaced the brushes, at least we were getting SOME charging.  We are concerned about
1. my soldering job - although it's ugly, it does seem to be a good connection.  We checked continuity.  Although some solder did wick up the copper wire - does this really matter?
2. reinstalling the brush holder.  I'm fairly confident we put in the bushing/insulating washers correctly, but we didn't actually check this BEFORE we took it apart.  

So I've done some searching both here on the forum and on the web.  I've found lots of info on bad rotors (no light at all) - but nothing to tell me what it means when the Gen light stays on all the time (except no charging).  What do I check next?

[Bob_Roller]

The charging system guide from Motorrad Elektrik says that a stator issue will cause the light to come on bright .

To check the stator windings, remove the three wires from the stator case, these are the output wires, place a multimeter on one of the terminals with the meter set to the ohms scale, touch the other lead to one of the other terminals, you should get around .6 ohms, touch the lead to the remaining terminal, you should get the same reading .
  
Not that you did anything wrong, but if you didn't have this problem before working on the brushes, I would go back and check your work again .

The placement of the fiber insulating washers is important .

[msbuck]

The placement of the fiber insulating washers is important .

So can you tell me how they go?  I have put them inside the housing.  We can't find any pictures, descriptions anywhere of the placement of these.  

Basically I installed... brush holder onto housing.  Outside of housing I put a washer and nut. (I think this just installs the spade connector.)  Inside of the housing, on left (looking from backside through stator wires) I put bushing, insulator, wave washer, nut.  On the right I put insulator, wave washer, nut.  Now we're wondering if the insulator goes between the brush holder and the housing on the outside?

[Bob_Roller]

Going on the photo in the charging system guide, there is an insulating washer between the stator case and the brush holder .

I think that's where your problem, with out the insulating washers between the stator case and brush holder, the excitation voltage from the voltage regulator to the rotor, is going straight to a ground, causing the "GEN' light to come on brightly and never go out .

[donbmw]

I replaced the brushes on my R90 this winter and had the brush spring slip down the side of the brush. I did not find this until I started the bike and the Gen light stay on. Double check the brush spring are setting on top of the brushes.

Don

[msbuck]

   Moved the insulators and no change...

We've checked the stator and it checks out good.  I guess tomorrow we test the diode board and go from there.  

Another question about my brush replacement.  The new brushes did not have any insulating sleeve around the cooper wire.  I did not read snowbum's article (slap head)  until after I had soldered the brushes.  I did not move the old sleeves to the new wires, so they are bare copper wires.  Does this matter?  

[Rob Valdez 79 R65]

I did not move the old sleeves to the new wires, so they are bare copper wires.Does this matter?  

That could very well be the problem.  But I don't know, for sure.

Here is a picture of mine, if it helps with the washers and stuff:


^{click for REALLY big}

[msbuck]

Thanks for the picture, Rob!

Both Graham and I have been stewing over this all night.  Now what we've decided...I've put the insulated washers on each bolt, both the positive and the ground.  We were thinking that the two insulated washer should go only on the positive side, one in the front between the housing/holder and on the back between the housing/wave washer.  I can clearly see from your picture that there is not an insulated washer on the ground side (at least in the front.)

We were planning on taking Graham's front cover off this morning to see how his was set-up, but with your picture that might not be necessary.  Let's try this one more time - fingers crossed. please!  

[msbuck]

  Hallelujah!  Both insulator washers go on the DF side- one on each side of the stator housing.  Thanks guys for all the help.

Now I have another problem....transmission vent bolt - stripped the threads in the case.  

[Semper Gumby]

Yes I moved the insulation on to my new brushes.  Also don't trim the braided copper wire to the brush.  The brushes needs the slack so that as they wear they can pull the wire farther from your solder connection.

Probably stating the obvious but....if you have mucked this up then just go buy another set of brushes.  They are cheap compared to getting towed off the road.

Good luck Aïda.

[montmil]

...Now I have another problem....transmission vent bolt - stripped the threads in the case.  

The one on top of the final drive case? I'd be inclined to clean the vent bolt and the case r-e-a-l-l-y well and JB Weld that puppy back in place. No kidding. That's what I'd do. Honest. Anything else is gonna get costly, I'm thinking.

Monte

[msbuck]

Monte - what about the negative battery wire?  That's where we disconnect to be able to remove the front cover.  

Hmmmm....got me thinking here anyway.  Thanks.

Semper - the insulated sleeve doesn't seem to make a difference.  It's working fine now, just had the insulator washers in the wrong place.  We checked the charging and I'm getting the full 14 volts at charge.  Whew!  I'm glad I didn't have to start all over.  

[Ed Miller]

...Now I have another problem....transmission vent bolt - stripped the threads in the case.  

The one on top of the final drive case? I'd be inclined to clean the vent bolt and the case r-e-a-l-l-y well and JB Weld that puppy back in place. No kidding. That's what I'd do. Honest. Anything else is gonna get costly, I'm thinking.

Monte

And run a longer ground wire to some other location?  I've been meaning to do that myself one of these days.

[Bob_Roller]

If you change the battery ground connection, just make sure the cable or wire is heavy enough to handle the electrical load of the starter, the starter is grounded to the engine case through physical contact of the metal case of the starter touching the engine case .

The starter draws 150-200 amps when operating .

Any undersized connection would most likely melt under the load .

[montmil]

Oops, Aïda. I was thinking of the vent bolt on top of the final drive case.

Another thought... careful. Perhaps tap the hole for an SAE bolt just slightly larger than the OEM. Use some heavy grease on the tap and you'll catch the chips. Thread a little, back out, clean and re-grease, thread a little more...

A short bolt could be gun drilled for the vent hole.

I often get in trouble when I get to thankin' too mucho.

Monte