Furnace Short Cycles Off and On

Problem Solved. I finally had a chance to remove the furnace and the problem was very obvious. A round sheet metal cover was wedged directly in front of the blower, substantially reducing the air flow. This is very sloppy on the part of Keystone for not running the furnace and detecting that the air flow was way down. The original owner used the trailer in warm weather and never picked up that the furnace was under performing.

Thank you all for the input. Rogerck.