Insane, growing, electrical problem

[mrlmd1]

I'm going to take a different path here and say the problem may be with your battery. If it measured 11.75V at rest, after a 1/2 hr. of riding or not, it is dead. LIke, almost ZERO charge.
A fully charged battery should read 12.6-12.8V, not 12.4. And if you measure the voltage right after taking it off the charger, you are reading a "surface charge" which is inaccurate. The battery must sit at least 1/2 -1 hr. to let this dissipate and then you will get an accurate reading of it's voltage. And if you let it sit 24-48hrs, it should maintain that voltage.
I would check your battery's resting voltage again after you remove it from the bike or disconnect it. Then charge it completely, and then get it load tested.
It may have a bad cell causing your charging voltage to go all over the place.

I would also hook up anther good battery, even an auto battery, to the bike via jumper cables (being careful not to short anything out against the frame or each other) and measure your charging voltage again at slow and fast rpms to see what your system is putting out, before you start digging into it.

If your battery checks out good with a load test and holds it's charge, then the problem is elsewhere. Likewise for the voltage check when you hook up a good battery and run the bike.

[OldNTired]

Originally Posted by Water Warrior

Looks like a process of elimination to find the problem. Carry on and good hunting.

Thanks, it will be a grind unless I get lucky.

[OldNTired]

[quote=Road_Clam]

Originally Posted by OldNTired

Thanks for the reply. I thought I answered this though, maybe I wasn't very clear. And, I forgot to mention that over most of the winter I kept the battery on a tender.
Anyway, I did test it at high RPM's, I could have written it clearer, but I did say that the voltage was lower at higher RPM's. At idle it was about 11 to 11.5V, at about 4000RPM it drops to about 6.5V.
The battery was at 12.8 off of the tender. I know it needs to be 13.5 to 14.5V when charging, that's half of my problem and the reason I was checking out the rectifier.
You might very well have an idea with that question about a ground, but wouldn't that have drained the battery while it was sitting? I don't know. It stayed at about 12.6 all winter, I put it on the tender when the temps got really low around here. It is in a garage, but not a heated one.
Any ideas where I might look for a short? I've trid eveywhere but in the headlight bucket.

OK, now i'm thinking you have a bad "phase" in your stator output. d/l the factory service manual and go to section 6-8 and do the ohm, and "no load" tests for your stator. If your stator checks out then the only component left to be faulty is your R/R .[/quote:1b7q71br]

As I wrote in my first post, I did do the OHM tests on the stator. The results looked good.
As for the 'no load' test, well, that'll have to wait until I get power and can test with it running.
One thing I am not sure of though: on the 'no load' tests, I know that I should test for 60V AC, but how do I do that? Do I need a ground, or do I check between pins from the stator?

[OldNTired]

Originally Posted by alantf

From your description of the fault, it's possible that there's a problem with the silicon control rectifiers, which control the charging voltage.[attachment=1:30kpbjeu]img042.jpg[/attachment:30kpbjeu][attachment=0:30kpbjeu]img036.jpg[/attachment:30kpbjeu]

Sure seems that way, what threw me off, and still does, is that all the info says 'overcharge' when they talk about a R/R problem - and I have the opposite problem, too low of a charge!

[OldNTired]

Originally Posted by mrlmd1

I'm going to take a different path here and say the problem may be with your battery. If it measured 11.75V at rest, after a 1/2 hr. of riding or not, it is dead. LIke, almost ZERO charge.
A fully charged battery should read 12.6-12.8V, not 12.4. And if you measure the voltage right after taking it off the charger, you are reading a "surface charge" which is inaccurate. The battery must sit at least 1/2 -1 hr. to let this dissipate and then you will get an accurate reading of it's voltage. And if you let it sit 24-48hrs, it should maintain that voltage.
I would check your battery's resting voltage again after you remove it from the bike or disconnect it. Then charge it completely, and then get it load tested.
It may have a bad cell causing your charging voltage to go all over the place.

I would also hook up anther good battery, even an auto battery, to the bike via jumper cables (being careful not to short anything out against the frame or each other) and measure your charging voltage again at slow and fast rpms to see what your system is putting out, before you start digging into it.

If your battery checks out good with a load test and holds it's charge, then the problem is elsewhere. Likewise for the voltage check when you hook up a good battery and run the bike.

My fault, I worded that part a little strangely.
After riding, the voltage was low. After charging, the battery stayed at 12.6 to 12.7, even after sitting for months! I didn't put it on the battery tender until the end of December when the temps got really low here.
I like your idea of testing with another battery, though. If the bike battery does have a problem of some kind, that would show it up. But, like the static test on the stator, that'll have to wait until I fix the power problem so I can get it running.

[Road_Clam]

Originally Posted by OldNTired

One thing I am not sure of though: on the 'no load' tests, I know that I should test for 60V AC, but how do I do that? Do I need a ground, or do I check between pins from the stator?

You jump each stator phase wire. So one tester lead to one phase wire, and the other test lead to another phase wire. You end up doing 3 pairs of tests.

[OldNTired]

Originally Posted by Road_Clam

You jump each stator phase wire. So one tester lead to one phase wire, and the other test lead to another phase wire. You end up doing 3 pairs of tests.

Thank you. Sounds easy enough to do, once I get the power issue solved so I can get the bike started.
I'll be tied up all day tomorrow, but after that I'll have a few days to focus on this.

[Road_Clam]

Originally Posted by OldNTired

Thank you. Sounds easy enough to do, once I get the power issue solved so I can get the bike started.
I'll be tied up all day tomorrow, but after that I'll have a few days to focus on this.

Remember my #1 tip is test the simple things FIRST. Then work your way through by process of elimination. People tend to wildy guess off on too far of a tangent when it comes to certain issues, and they end up spending way more money replacing non-faulty components when they should have done some flow chart type systematic testing, and found the issue correctly. At least you are asking the correct questions, and you will figure it out. Electrical gremlins can be a real frustrating PIA to diagnose.

I had an intermittent stalling and ill running issue and would occasionally. blow a main fuse with my GPz a few years back. It all of a sudden appeared in the spring (ran fine the prior to winter storage). I was thinking a bad connection with respect to ignition/spark. It took me a month of time consuming disassemble to finally find the problem. friggin MICE had chewed a small portion of my fuel injection wiring harness, i didn't see the damage until I removed the tail section and pulled the wires away from the plastic inner fender. Several wires were chewed right to metal and shorting out ! I was so pissed ! Now I am on a mission with mouse traps !! But as an example you can see how frustrating electrical problems can be, especially "ghost" electrical issues than are intermittent.

[alantf]

Originally Posted by Road_Clam

Now I am on a mission with mouse traps !!

When I got a mouse problem in my workshop, my traps never caught anything. Then, a friend introduced me to something MUCH better. They're sheets of cardboard, about 6" square, smeared with the strongest glue I've ever known. Once the mice touch them, there's no way they're getting free. I even caught two on one board, one day. :2tup:

[mrlmd1]

The benefit of that compared to poison bait is that you know where they are, instead of going to some hidden place to die and then having to track down the smell to find them.