It could be an actuator for the blend air door or there have been a few issues with the door being stuck or the shaft that attaches to the actuator is broken.
However, you asked for an approximate cost. According to my manual, the air temperature actuator shows 0.4 hours to replace. So, it's a little more than a half hour labor. The part shouldn't be much more than $40.00.
If you want to replace it yourself, and you can, first here is a link to check out that shows how in general one is replaced:
Here are the directions specific to your vehicle. The two attached pics correlate with these directions.
2006 Chevy Truck Equinox AWD V6-3.4L VIN F
Air Temperature Actuator
Vehicle Heating and Air Conditioning Air Door Actuator / Motor Service and Repair Procedures Air Temperature Actuator
AIR TEMPERATURE ACTUATOR
AIR TEMPERATURE ACTUATOR REPLACEMENT
1. Remove the instrument panel compartment.
2. Disconnect the electrical connector from the air temperature actuator.
3. Remove the air temperature actuator screws from the HVAC module.
4. Remove the air temperature actuator from the HVAC module.
1. Align the air temperature actuator with the door shaft and rotate into position.
2. Install the air temperature actuator screws to the HVAC module.
Tighten the screws to 1.5 N.m (13 lb in).
NOTE: Refer to Fastener Notice.
3. Connect the electrical connector to the air temperature actuator.
4. Calibrate the actuators by simultaneously pushing the A/C and RECIRC buttons on the HVAC control module three times each, within two seconds of initial push.
- The A/C and RECIRC button LED's will flash while this calibration is taking place.
- The calibration will take anywhere between 10 to 30 seconds depending on battery voltage.
- The LEDs will quit flashing when the calibration is complete.
IMPORTANT: Any time an actuator or the HVAC control module is replaced, the HVAC control module must be calibrated to ensure proper air distribution.
5. Cycle the ignition and verify proper operation.
6. Install the instrument panel compartment.
What I would suggest is to remove the actuator and see if it moves when you change temperature from cold to hot and back. If it does, the actuator is good. At that point, we will need to see what has failed in the heater box.
Please feel free to let me know if you have other questions or need help. I hope this is helpful.
Images (Click to enlarge)
Thursday, November 28th, 2019 AT 8:03 PM