I wanted to post in the HVAC FORUM but i would get better info on this forum I have a 2004 4X4 SCREW LARIAT with 7900 miles I have been having problems with the HVAC HEAD UNIT it shuts off by itself This has happened 6 times since i had this truck I had the dealer look at it one time and they told me CNV all was fine On 6/27/06 my HVAC HEAD UNIT shut off by itself again I turned it back on and all was fine I left the truck out for a couple of hours I went back out to put it in the garage turned on ac blowing hot air Before i went to the dealer i went to this forum and found a post from QUENTINabout a TSB on the HEAD UNIT I told my service advisor about this and he told me if they cant duplicate the problem iam SOL So 12 hours later they called me and told me that my ac is working fine And could not find any problem he told me that they took it for a road test and all was fine BTW my truck had 7892 miles when i dropped it off When i picked it up it had 7892 miles This is my invoice 7792 DID NOT VERIFY CONCERN BLOWS 55 DEGREES PEROFRM AC PRESSURE TEST PASS LOW SIDE 34 PSI HIGH SIDE 165 PSI NPF CC82 SORRY FOR THE LONG POST