Thank you for the kind words and your continued business!
For your 2014 Jayco Swift SLX 15BH the MaxxFan Plus Roof Vent w/ 12V Fan, Thermostat, and Remote - Powered Lift - 10 Speed - Smoke # MA00-04500K will fit your 14" x 14" roof vent opening perfectly, but you will need to make sure your roof is between 2" and 6-1/2" thick. If it is not you can build it up using lumber.
Regarding how to get power from your trailer to the fan, there is a few different ways. The light you mentioned may... view full answer...
The Ventline Ventadome Trailer Roof Vent # V2092SP-25 that you're referring to doesn't actually have a fan, it is just a roof vent.
You could technically add a fan to your roof vent, with a fan blade # BVD0215-00, and a motor # BVD0218-00, however the wiring harness and mounting brackets aren't offered so that is something you'd need to supply.
Instead, a much easier solution is to swap roof vents alltogether with the Ventline Ventadome Trailer Roof Vent w/ 12V Fan # V2094SP-28.
This... view full answer...