I installed a fantastic fan on my 318SAB Cougar that I traded in on a new CC34RL. I used the 12V lights circuit that was right next to the vent in the kitchen area. I also traded out all of the 12V light bulbs to LED lights to lower the Amp/ volt draw through the circuit. The fantastic fan worked with a remote and would close if the sensor got wet, I would run the fan all night on a slow speed to draw air through the camper on a warm summer night if the AC was not required.
2016 34RL CC; 2008 Ram Mega Cab 2500HD, 6.7L, 68RFE 6 speed, 4X4, Smarty S67