When you say front fuse box, there should be two, or more, 1 for, lights, signals , horn, anything pertaining, to the operation on the road of the coach) a second for the interior of the coach , furnace , water pump, interior lights. If none of the fuses you found were labeled for coach interior items , you have to look for another fuse panel.
Frustrating , I know , I've found fuses in about 10 locations around my coach.