it would actually be in the CEILING of the wet bay, but may not be able to be seen since it's probably right behind and above the wet bay 'panel'... I've never been able to find mine either.
I should be in line with the floor registers in the coach itself, as it's simply another 'register' hole, but in the ceiling of the lower bay.
I suppose you could run a test: on a cold day, take the temperature of the wet bay, then start the furnace and take another test of the temperature after several minutes.
'14 Palazzo 33.3 bunkhouse 34' diesel
KingTailgater2 Dish HD, 100w/5a SOLAR, BlueOx
100,000+mi since '14 - US, Alaska, Canada - Northwest, GA! (also, '14 Gulfstream Amerilite and '07 ForestRiver Rockwood) : )