interesting, as I just noticed our son's rockwood signature ultralight has the front vent, with no fan, but it certainly has some 12v wires showing there. I imagine it's run for the fan, if the owner wants to add one later... if you remove your vent you'll probably find it.
'14 Thor Palazzo 33.3 compact diesel 100k+miles since '14... US, Alaska, Canada...
AND a '14 Gulfstream Amerlite
AND a '07 ForestRIver Rockwood