I am sure some (or all) have heard of this problem, but I need some help because its driving me nuts! I installed a new battery in my wifes 2002 Chevy Tahoe. Immediately afterward, the controls would only blow heat through the defrost setting, no matter what the dial was set to. Also, when I tried the AC the light on the button would just blink and never turn the AC on. Its a real pain in the butt that this happened just from a battery swap!!!