How is the air coming out of the blower? Try taking off the hose and looking for debris or worse, a critter next in the hose feeding the trough. You could have construction debris in the hose or trough. Maybe disconnect at #8 and try blowing air back to the blower housing, disconnect from the blower of course. In my old class c, I had a rather large hole in the hose feeding the bedroom in the rear. You may have a hole or bad kink in hose #2.
2018 Hurricane 29M
CHF, Saf-T-Plus, SumoSprings