I added a Fantastic Fan to our 1007UD, the dealer service department did the installation for us. I had purchased the fan through Amazon and when I went to the dealer to purchase supplies for the installation, my original salesman begged me to have their service department do the installation because they do so many and he did not want me to potentially damage the roof of the camper. To answer your question, they took power from the wiring that runs along the outer portion of the ceiling. I thought they would tie into the wiring in the center of the ceiling that supplies the lights, but they opted to tie into the wiring that runs along the outer portion of the ceiling. The installation was very clean, I'm sure that I could have done it myself, but I paid $105 and it was money pretty well spent. Not sure how long it took to clean up the caulking on the roof, but the wiring could not have taken more than 5 minutes once the roof was raised and the technician climbing inside.
2014 Ford F150 SCab 4x4 5.0L Tuxedo Black Metallic
2017 Jay Flight 21 QB Elite
2015 Jay Series 1007 UD (sold)
"Life is so very short, eat the dessert first".