well when i bought my truck i didn't notice on the test drive that my a/c was blowing out of my defrost vent. so on the way home i notice that everything was working just blowing out of my defrost. i thought to myself if everything is working it can't be a bad fix. well i have had my truck for about 2 months now and just got around to working on it since its warming up here in central bama. i took the unit out of my truck brought it to the kitchen table and went to work on it. i changed the 4 o-rings in it put it back togather and in about 45 min. total i now have cold and hot air coming from my vents what a simple fix. if anyone needs the info on it let me know. to my knowledge this only works on the fully electrical ac head unit with the scroll fan ****.