this ac heating system has me completely baffled, my problem seemed to start oneday when the truck started hesitating and my check engine light came on,(i had to replace the coils)at that point my AC/heat hasnt worked right at at all, I can put my AC on recirculate and set it on body and feet and will get SOME sort of cool air for a while but thats it. in the winter straight cold air no heat, full of freon, i can hear the blend door open and close please help!