To the electrically minded

to be killing a battery like that something has got to be hot big time.
what are the battery cables like, new or in real good shape?
since you said you can pull the main fuse and it charges like its supposed to the only thing that can draw that much without making something smoke would be the headlight, you should be able to unplug it and do a short ride.
what is bothering me is it charges like it should then drains itself.

did all this charging problem start after the bike was dropped?

If it was a subcircuit, wouldn'tthe problem stillbe there when using the capacitor?

I'm just starting to think that the extra load (albeit small), of getting the battery voltage up to 14v (in your case 15v) is either heating up a connection, or wire, or is causing the rotor to slip. When using the capacitor, the voltage can jump up immediately so that little extra load is not there. That extra load (2 amps or so) would only be temporary until the battery climbed to 14/15v, but in your case it acts as a catalyst to get the rotor slipping or a connection heated up. Once it's slipping, or heated, the system can't recover.

@BSK

I agree, all the amps have to be going SOMEWHERE, heating something up. The charging issue pre-existed the fall. It happened when I was trying to bump start it last year, and dropped it after I was way tired from 15 previous attempts and it bucked on under me.

Positive battery cable to solenoid brand new as of October. Negative strap not new but clean and nice. Cables from regulator additional and new, thick, and clean.

I was think of load testing WITH battery by warming bike up on ride, pulling all fuses but main, and then connecting two 55W headlights directly to battery with bike running. Then would have 110W "running" load, bypassing all wiring, and seeing how it does.

Also, thinking of going to a parking lot and doing circles at 3k rpm, first starting only with main fuse and adding in to find which circuit bad connection must be on, or the other way starting full load and reducing.

@loudhvx

Another possiblity is that it is a subciruit that has a heat related or intermittant partial short. The capacitor tests I've done have been sitting still, no virbration, or 2 minutes -- not on the road, full usage.

I have recently blown the subcircuit fuse that runs the fuel/oil/neutral light, tachometer, high brake light, and turn signal controller. Thinking it was the self checker , I removed it temporarily and haven't blown a fuse again. However, in light of recent events, I think that may still be the suspect wiring.

However, since the circuit by definition runs low duty cycle loads compared to running time, can anyone think of a good way to test out this light or hairline shorts or bad connector -- just voltage drop the circuit?

I will definitely take the stator cover off tonight and have a look at the rotor in action. I will first check as is, then attempt to retorque the mounting bolt. Anyone know a safe way to apply a light friction to it at say 3000 rpm to see if I can make it slip? Leather belt too risky??

On a side note, is there a way to run a low current, but different sense line. Will the attached diagram work to do a low current sense line to isoloate that wiring during testing?

the more I think about this, the more puzzeled I get
thinking this thur

the charging system does not function when riding

the stator and rec/reg have been replaced

the battery is new and charged

no fuses are being blown

no hot or melted wires

the charging system works with caps

Now, are you sure the rec/reg is correct fot the bike / charging system, it seems to me that the rec/reg is not being sensed by the battery since you did the volt meter while riding test

Several pages back I latched on to the fact that the bike seemed to run fine with only the main fuse. I'm going to look at your wiring diagram and see what sort of procedure we can go through to isolate the offending circuit.

I would guess it is a device that is getting warm as you run the bike and possibly shunting current to ground.

So I guess you can run the bike until its warm to start the problem (<13V at 4000rpm) then start pulling fuses? Are your headlights always on?

Be back when I study the 750N1 wiring diagram.

@BSKZ650

Seriously, it defies logic. When I find this problem and fix it, I'm getting stupid drunk becuase I'm tried of thinking about it.

@Inline

Yeah, it's a puzzler. Headligh is always on. I'm thinking of designing a fuse replacement that constitutes a switch so while I'm going I can flip that circuit on and off. Running with a voltmeter and the ability to dynamically disable only one ciruit, I should be able to see that that one is the problem, while also being able to safely return function on the road. I have a high resolution scan of the wiring diagram, as well as easier to read redraws that I did. They are available here

www.davidpurdy.net/Wiring.pdf
www.davidpurdy.net/redraw.pdf

Post edited by: dnpurdy, at: 2007/06/12 12:36

I was just looking at your wiring diagram you posted, the factory one, and went back several pages.
The brown wires " sense wire " goes two places, 1 the ignition switch, and the fuse, possible that there is a bad connection in the switch that vibration would make this happen?, I was thinking that it is loosing the sense connection thus not charging

Well, lack of sense wire should only have the affect of over charging. A disconnected sense wire means the regulator never switches the SCRs on to shunt to ground. The only effect that would produce undercharge with the sense wire is if I have a sense to ground short.

Hmm...interesting thought there. Sense wire is after the 30AMP main fuse, but before the bus of 10AMP subcircuit fuses. If I'm getting a small short to ground along the sense line, that could eat up wattage without necessarily pulling the 30 AMP fuse.

Also, could my ignition switch just be heating up? Could that be my "bad connector"?

Well, no, if pulling one of the 10A fuses fixes things then the problem MUST be after the fuses, not before. Running with just the main fuse would still cause any problems in the ignition switch to affect the system (but its always a good idea to check the switch anyways - mine was shorting and warming up!)

Well, if you do some parking lot tests you can pull all the small fuses one by one without needing lights, brake lights, signal lights, accessory power...

dnpurdy wrote:

On a side note, is there a way to run a low current, but different sense line. Will the attached diagram work to do a low current sense line to isoloate that wiring during testing?

You don't need the resistor. Just run the sense line direct. The regulator's detector shouldn't need much current.

dnpurdy wrote:

Well, lack of sense wire should only have the affect of over charging. A disconnected sense wire means the regulator never switches the SCRs on to shunt to ground. The only effect that would produce undercharge with the sense wire is if I have a sense to ground short.

Hmm...interesting thought there. Sense wire is after the 30AMP main fuse, but before the bus of 10AMP subcircuit fuses. If I'm getting a small short to ground along the sense line, that could eat up wattage without necessarily pulling the 30 AMP fuse.

Also, could my ignition switch just be heating up? Could that be my "bad connector"?

If you ground trhe sense wire, the regulator would put out more voltage.

If the sense line is higher than 14.5v (relative to the regulator's ground), then it shunts.