Conversation Between Johnny Hotspur GT and morgan13

Hey mate!
I can't stop seeing your name in all the topics im reading througth but mine case is diferent, hope you can advice me on it
I have a bentley continental for over 2 years and everything was fine until now we can say.
The other day I was driving and out of the suddent the car went off and impossible to make it crank again, I put ignition, all ok every screen is on, i want to start and everything comes down and voltage shuts down do 7/8V
the moment the car stop it drained completly the auxiliary battery but not starter one,

I have codes related to short circuit on terminal 30 but even disconecting the alternator nothing changes.
The battery has been replaced 2 month ago because my rear window were not working properly
the starter seems to work, because when I try for the first timethe engine is trying to crank but not even 1 sec but you heard the engine turn.

can you please suggest me some ideas or things because im kind of a bit lost