Battery not charging

[Hann]

Any updates on this?

 

[GSyoda]

Hi, I hope it works out for the best, but the stator being down to earth doesn't bode well. I think what's happening is that just one phase has shorted with the chassis. So when you unplug it for testing there is no path for the fault current to take via the chassis because it's completely disconnected from the 12v system. Hence the voltage tests look fine. With the plugs connected and everything back in circuit, then there is a fault path between the stator and the 12v side of the system.
If my theory is correct then you ought to be able to measure AC voltage being generated between 2 of the phases and the bike chassis with it unplugged, but I hope I'm wrong for your sake.

 

[knutk]

Hi, I hope it works out for the best, but the stator being down to earth doesn't bode well. I think what's happening is that just one phase has shorted with the chassis. So when you unplug it for testing there is no path for the fault current to take via the chassis because it's completely disconnected from the 12v system. Hence the voltage tests look fine. With the plugs connected and everything back in circuit, then there is a fault path between the stator and the 12v side of the system.
If my theory is correct then you ought to be able to measure AC voltage being generated between 2 of the phases and the bike chassis with it unplugged, but I hope I'm wrong for your sake.

I think you may be on to something.

Anyway, this issue needs a proper fault-finding, done systematically.

As far as I understand, it's not about the battery, so no point wasting time on the battery. It's all about the generator not supplying the charge.

The stators have an internal resistance of less than 1 ohm (I have read somwhere that it is 0.6 ohm), so a QUALITY multimeter is required.
Stators that are grounded by porpose do exist, but rarely found on anything but low-complex vehicles.

A schematic of the system would be most helpfull. This may call for some investment in documentation or equipment.
I do appreciate the reluctance to spend money for required equipment. However, this must be compared to the wasted cost of a faulty diagnose. And keep in mind, 1 hour of shoptime gets you a long way in buying necessary tools.

 

[Bazza]

Hi Boys, finally stopped staring at my bike in the garage hoping it will magically get better...... didn't work! and got it to BMW. it was indeed the Stator fault with a price to fix of £2.5K....
BMW UK not helping with cost as a good will gesture so eventually did a trade in 'as is' and think I got a pretty good deal on the demo 1250gs.... so back to it, only thing now is 12 months off a bike and my bike gear must've shrunk in the wash