heater controll issues

waterworkerwaterworker Member Posts: 1
edited August 2018 in GMC
I only have vent with my heater, the others settings will not change. The defrost and floor heat will not work. the actuator seems to not work.


  • imidazol97imidazol97 Member Posts: 26,931
    edited August 2018
    Vehicle model and year would help. But...

    1) I believe you diagnosed your own problem. The mode actuator, which is probably electrical, is not working. Might be the connector and contacts there, but most likely would be a failed actuator.

    Take off the under dash plastic and try to visually see the actuators. Search internet for the year which you didn't mention and the vehicle model, and the words mode actuator location. You'll probably find a diagram to help.

    Most actuators have a rotating hub which can be seen and watched for movement while someone else changes the mode, temperature, recirculate settings with the key ON and you watch underneath.

    Some actuators are easily replaced with a correct part from Rockauto or other source. Often one screw holds them in place helped by prongs and shape.

    2) Sometimes there a break in the arm or the flap inside the HVAC box that stops movement. When the actuator is removed, that can be verified to be working correctly.

    Good luck.

    2014 Malibu 2LT, 2015 Cruze 2LT,

Sign In or Register to comment.