[xpa 750 overvoltage]

42 minutes ago, Pressureangle said:

Ok. The answer lies in notes 1 and 5. 

The wht/blk connector mate on the frame harness is suspect. You'll have to do some patient sciencing here. 
Pull the plug very slightly apart so you can measure the actual voltage in from the headlamp circuit. That should measure within .2 volts of battery. If it measures a difference of more than .5 volts, you have a meaningful connection fault. If you measure a high differential, measure at the next accessible point upstream; if the mating connector in the harness is not molded as the regulator side is, probe the wire where it meets the terminal to see if you have a bad crimp. I hate poking holes in wires, but if you have to to measure voltage in the harness before and after the plugs it's necessary. I'd start by chasing the accessible points first. I don't think it will take very long to isolate the problem point.

Another point of order is to use your meter to measure differential between the regulator case and battery negative. Though you've run a bypass, it's still important to know the ground is sufficient not to have a differential. 

I'll do all the tests you suggested. thanks a lot for your help!!

[xpa 750 overvoltage]

14 hours ago, Pressureangle said:

I'm not familiar with the particular layout of this regulator. You have 2 input wires from the alternator, yes? Or 3? Then you have a Battery + going out to charge, and a no-charge lamp wire? You might try grounding the bulb wire to see if that's the ground reference. 

the layout is 

 

-2 yellow wires from regulator

-1 red wire +12v to battery

-2 wires > 1 black voltage on key 1 white to no charge lamp

 

i've attached the schematic of the regulator provided by @kiwi_roy in this forum and an image of the regulator itself

 

[xpa 750 overvoltage]

if you mean directly from the regulator i've tried to connect the wire (black wire from ducati energia regulator in a 2 pin connector, the other one is for the battery bulb) directly to the battery positive with no success. or you mean an other operation? 

[xpa 750 overvoltage]

i've used a 2.5sqmm wire to ground the the regulator body and i've tried also to connect directly to battery negative with no result. i'm afraid that the problem is in the "positive side" of the voltage reference but don't now how to change the actual configuration to a new reference point to test. Thanks for your answer!!

[xpa 750 overvoltage]

Hi, i'm new in the forum, sorry if it isn't a v11 related problem but i hope you can help me. I'm experiencing a very strange problem, from the regulator of my 1997 guzzi xpa 750 (ducati energia) i've a voltage from 13 to 17v accordingly to rpm increase, two batteries are gone and changing the regulator didn't change the situation. From the stator i've circa 90/100v ac at "max" rpm. i've read about this issue appened to other owners, have you experienced something similar? i've read several interventions about this kind of issues from @Kiwi_Roy user here. ì've attached a video to better explain. Thanks and sorry for my english.

Filippo

https://sendvid.com/z7jdcd3b