I have 2004 Trailblazer and had the battery replaced two days ago. After I drove away from NTB my AC, which was working fine prior to battery replacement, will not blow out of front vents When AC "mode" is set to blow out front vents it will only blow at my feet and windsheild. Seems to be cooling well, except air no longer comes out front vents. The NTB people said that in GM cars the system sometimes needs to reset itself and it could take a few days or more and will work like it should when it resets. NTB said the dealership would tell me the same thing. What should I do?