Wiring harness beneath the seat. Question.

[Purloined]

Marty NZ, are you thinking that it is possible for the voltage regulator itself to be draining the battery while the key is out of the ignition?

I don't believe there is an innate problem with the charging system of the motorcycle. All things being said, it runs/charges fine. But if left unridden, the battery has been draining.   

I have been reading on this forum posts about the importance of a proper wire to ground for the regulator.        The bad wire that came  out of the ECU harness under the seat is still in the harness going to ??.       Some have suggested it might be from the regulator to ECU fastening bolt/ground. I should make sure the regualtor has a good and proper ground. And maybe add one. 

Still, battery drain while the bike is off is the problem. 

[gstallons]

I would make certain you had a good ground to the engine . I would put it at the battery cable ground .

[Chuck]

Quote

Still, battery drain while the bike is off is the problem. 

I learned the hard way that if you have a USB gizmo hooked up to a battery, it will kill it dead as a mackerel if you forget to unhook the USB gizmo and let the bike set over a period of time.

[fotoguzzi]

The regulator gets a ground through a captured nut, dodgy at best. Run a wire from the regulator case to engine block so you have a solid ground connection.

[MartyNZ]

12 hours ago, Purloined said:

Marty NZ, are you thinking that it is possible for the voltage regulator itself to be draining the battery while the key is out of the ignition?

I don't believe there is an innate problem with the charging system of the motorcycle. All things being said, it runs/charges fine. But if left unridden, the battery has been draining.   

I have been reading on this forum posts about the importance of a proper wire to ground for the regulator.        The bad wire that came  out of the ECU harness under the seat is still in the harness going to ??.       Some have suggested it might be from the regulator to ECU fastening bolt/ground. I should make sure the regualtor has a good and proper ground. And maybe add one. 

Still, battery drain while the bike is off is the problem. 

The first subject is current drain. You have some good suggestions above already. If you haven't found the leak yet, you need to keep disconnecting things until you do. 20 milliamps is the sort of leakage current you can get across wet and dirty deposits, such as salt spray and road grime on the back of an unprotected starter. Or a switch filled with water.

Secondly, for the burned ground wire, the file I attached shows a circuit diagram. It shows one of the two ground leads that should both be in good order. Note that this lead has three connections: regulator, engine/gearbox, & battery. 2.5 sq mm is a good size cable. You may know it as 13 or 14 AWG. Kiwi_Roy has previously made a good suggestion about using an aluminium strap as a bonding lead between the regulator and engine..

[Purloined]

I've been sifting through the accumulated details that are cited in these posts in order to try to understand the arcane circulatory system (if in fact a 'system'? Maybe 'battle' is a better descriptor.) that sparks and rumbles in the wires of these bikes. Akin to certain subjects in school where I was terrified of being called on to mainline my thorough ignorance into the ears of my classmates. Never mind the teacher. I do know that electricity hurts when your cross two poles. I learned that at age seven when I joined the two sides of an outlet in our ancient house. I'll bet the scorch mark is still there. Beyond that, I give my deficiencies a wide berth as I'm sure no good will come from it.

But I've gleaned a lot from the anecdotes everyone here has shared about their experiences with similar problems and I'm grateful for the time devoted; advice offered. I have a couple of patient, electrically inclined friends who've offered to be chaperones in order to ward off the mushroom cloud I know I can generate in the dark recesses of a Moto Guzzi's electrical labyrinth. And I think I can rectify, or a least examine, a lot of the innate problems that have been described in bits and pieces with all your help. 

And after all this fatuous hubris-building, I think I should get me a Tesla, a few tweaks and I know it will be a screaming fast monster. What is the secret code? Plus and minus are cantankerous bedfellows.

Off I go.  

Thanks again, all,

Marcus

[Purloined]

I installed several new grounds, including one from the rectifier where I abandoned the old ground that was fastened to it and cleaned up stuff as best I could and reassembled everything.  The bike seems to start more easily and run much better and more smoothly. I put a meter on the battery and all seems normal, so no drain. Hopefully a new normal of normal Moto Guzzi electrical bliss rules from now on. Just kidding, but thanks to all who had the patience to sift through my many onerous descriptions without throwing up your hands. The advice was invaluable.