ok so i had this trouble when i first got the car. The heater/ac only blew on full blast. thats not the real problem only the begining. So then finally i came around to changing the blower resistor pack being that was the cause of this. Oh yea mind you this my heater actually stopped working around december so i have had no heat all these months. it used to work when i first got it. then only worked on the highway. then not at all. Anyway last saturday i was at a stable point. seemed like the outside air was blowing in but it was good because it worked on 1 2 3 and 4. I had that working for a few weeks then one day i heard kind of like a bird chirping noise coming out of the vents and i know i have seen this problem on some forum but i cant find it now!!! well the day after the "birds" were making noises in my vents modes 1 2 and 3 stopped working again but the resistor pack is BRAND NEW. but heres the weird thing you can hear an electronic noise of something trying to open inside the vents when you turn the dial for each level and it works on full blast and has rediculously hot heat coming out which im not used to being that i didnt have that for a while. im thinking the heater box maybe was stuck shut or something and now is opened up? no clue but i brought it to my mechanic he said he needs me to bring the codes in to actually see whats wrong so i dont blow money on random parts. any idea where i can get codes read? I heard on here that Autozone does it for free? they are actually building one right in my town should be open pretty soon. thanks any input on what possibly could be happening?