The 2nd AC wiring is 110V, the Fantastic Fan needs 12V - that will pose a problem for you.
I have a Gulf Stream park trailer with a queen bedroom in the front and in the rear. The front bedroom would freeze you to death while you would bake in the rear bedroom. So, I installed a vent with a damper on it instead of the directional vent that came installed. It really helps.
We also set a fan up in the kitchen blowing back to the rear bedroom at night. That helps as well.
I ordered my camper and got a Fantastic Fan installed in each of the four vents...I can move some air through the camper!