I recently purchased a 2000 Holiday Rambler Endeavor diesel pusher. My wife and I just returned from the maiden voyage. It has two Duo Therm Heat Pump/Air Conditioners. The front unit heats and cools perfectly, however the back unit seems to just push ambient air. Any ideas? Coach has a freightliner chassis, a caterpillar engine and allison transmission. During the trip the message center lights on the dash went out. Took the coach to a Freightliner repair place and got no answers as to what the problem could be. Has anyone had similar experiences?