[AndrieK]

You’d have to run a D+ signal through the 12-pin trailer plug. Trailers in AUS generally don’t have reverse lamps or rear fog lamps, so if your 12-pin plug is wired correctly you should be able to use either pin 2 or 11.

If you then ever tow the trailer with a vehicle with a standard alternator, it’ll automatically isolate the blue wire on the BCDC as per the standard connection in your pic, assuming the other vehicle doesn’t have anything else connected via either pin 2 or 11.

 

[AndrieK]

Would 8 or 9 also work? I assume they may be triggered by ignition to not run all the time.

Eitherway, thanks for the diagram, I'm going to test some pins

In theory you could use any pin. The only time you'll have issues is when you try to tow the trailer with a different car, or a different trailer with the Everest. If the other car / trailer doesn't match your wiring, you'll end up with weird electrical issues.

I like @flow's idea though. I didn't know you get 3-pin Anderson plugs. Doing it this way will keep the BCDC wiring separate from the trailer lamp wiring, which means you won't run into issues with other vehicles / trailers.