I just got the heater to work in my '99 Safari. Two vents have good output , but the one across the coach is putting out very little airflow. I think it may have an abandoned (I hope) mouse nest in it. Was able to shove a shop vac hose up to the bend where it disappears under the floor. Found the insulated duct underneath behind the propane tank. I'd be willing to cut the duct there , clean it with the vac as far as I can and then couple the duct back together. The problem is I'm not willing to drop the propane tank, and if I don't drop it I will need at least 2 elbows on each arm. (very restricted access). Is there a way to clear the duct that I'm not aware of? Thanks for any ideas