We had a fan installed when we bought our trailer so I know it can be done. I like it. Our fan has a remote so I don't have to get up to adjust it, there is a glow under the trim that at night can be seen through the plastic, bothers the DW but not me.
Contact Jayco and see if they can send you the wiring diagram for your trailer.
TV: 2013 F350, Lariat, 4x4, CC, LB, 6.7L Powerstroke
FW: 2013 Jayco Eagle Premier 361 REQS
Additions: Onan 5500W LP Generator, Surge Guard TS,
.......Roof Satellite Dish, Vent Covers, Bedroom Vent Fan,
.......Rear Reciever, 12V DC Outlets (6), 320W Solar & Controller,
.......4 Lifeline AGM Batteries (600 Ah @ 12V),
.......Stereo Upgraded, Interior Speaker Upgrade, Amp