120 to rear a/c separately
I've wired my rear a/c in the same manner, but I don't see why you're involving any generator wiring. Keep it simple. No matter which input-- generator or shore power-- the incoming AC always go through the breaker panel before feeding throughout the coach. Just identify the circuit line feeding the rear air conditioner from the breaker panel and interrupt it at a convenient point. In my case the breaker panel was low in the bedroom wall, about nine inches from an easy spot in a right rear belly bay. Install a female receptacle on the breaker panel leg, and a male plug on the air conditioner leg. Done.
John & Diane, Fulltime since '12
2002 DSDP 40, FL, Cat 3126
John & Diane, Fulltimers. RVM103 NHSO
On the road since June '12 with Lincoln, the guard cat.
2002 Dutch Star 40, Freightliner, Cat 3126, 2004 Element