One or more heater & AC (HVAC) temperature and/or air delivery mode door actuator may fail, resulting in improper temperature or air delivery. If this occurs, fault code(s) should be stored in the HVAC control module which should assist in diagnoses.
Improper HVAC Temperature and/or Air Delivery Due to Failed Mode Door Actuator on GMC Suburban 2500
Average mileage: 177,500 (130,000–225,000)
10 people reported this problem
1994 GMC Suburban 2500 130,000 mi, Visitor
Cabin flapper door doesn't activate, stuck in position for HEAT. A/C ineffective.
1999 GMC Suburban 2500 225,000 mi, Visitor
the only location I got air is from the floor, if I unplugged one of the other actuators and left the fan off I could control where air would go, then I unplugged that actuator and can run the fan as normal. replaced both blend door and main actuators. will replace heat controller actuator this weekend.