JRAY1944 Report post Posted July 2, 2017 I have a 2000 Winnebago Adventurer on the Ford F53 chassis that will not distribute the AC air out the dash vents.....only sends it out through the defrost vents. Under heavy acceleration or engine load, the unit stops producing cold air. I know some compact cars had a device that shut off the compressor when this occurred....does the F53 chassis also have this feature? I am guessing the problem with the vents is a vacuum issue but don't know where to begin my search. Thanks in advance for your help. Jim Share this post Link to post Share on other sites
wolfe10 Report post Posted July 2, 2017 Jim, Welcome to the FMCA Forum. Yes, you have a vacuum problem. Could be nothing more than a vacuum line between manifold and HVAC control that came off, melted or cracked. The default position when no vacuum in the defrost vents. So, pull the engine cover and start "running the vacuum lines". Share this post Link to post Share on other sites