Hello my friends
The problem of the voltage regulator is a known issue. Everybody has a different solution, mostly by fixing the wires somehow directly into the regulator. I did not want to go this way, I do not like the "somehow" solutions. After several nights of searching I found a source of the connector as a spare part and after following investigations probably found a real reason for such problems and hopefully a way how to avoid it in the future.
I made two videos to this topic for you and placed it at my Youtube channel about XT660Z. Here you are with parts 1 and 2 :

https://www.youtube.com/watch?v=eHlpMSPzJQs

and part 2:

https://www.youtube.com/watch?v=jc6uRTHpu6I