So, we have a new-to-us 2008 Coleman Mesa Popup & I know next to nothing about popups or furnaces. The furnace will run initially for 5-30 mins, then turns off and sounds like it slows down 2-3 seconds. Then 4-5 mins of random, fairly quick clicking. When I remove the grill the Reset/Off switch has flipped to the Off position. If I turn the thermostat all the way down, move switch to Reset position, and raise the thermostat then it may come on. Sometimes this is right away, usually this is minutes to an hour later. The red error light blinks once with three seconds between indicating Limit Switch/Airflow problem. I don't see anything in the exhaust pipe or evidence of muddaubers. We have been randomly blowing lots of fuses (different ones) as I have been trying to figure out how this whole thing works. This process has blown a few as well, no circuits have ever flipped. Just bought a new deep cell battery so that is not the issue. Above scenario happened when plugged in at campground. From reading other posts, I am wondering if this is a limit switch problem but that is really just a shot in the dark. Can anyone shed some light on what may be happening or how to fix? Thanks in advance for any input!!