Always blows defroster and feet no matter what the setting
air blows,a/c & heat, why doesn't the mode work, only blows feet and defroster on 2004 Chevrolet Tahoe
POSS BLEND DOOR STUCK OR BROKEN SEEK DIAG AND EST
1 more answer , 1 more comment
Mode door or motor that changes the door position may have failed. This problem can be diagnosed with a Tech 2 GM scanner. A few other scanners may be able to do it also but the higher end scanners are needed.
Not just a OBD2 code reader.