Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
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When the temp output is only correct on one half of the dash, this is most commonly due to a faulty Air temp Actuator. This actuator turns the door internal of the HVAC housing to switch between heat and A/C as commanded by the control panel. The driver's side actuator is located under the driver's/center of the dash (image below). Inspect the electrical connector and wire harness for any loose, broken or damaged wires. If the visual inspection checks ok, remove the actuator and turn the door pin by hand. The temp output should now be correct. If not, the problem lies internal of the HVAC housing. It will need to be removed, opened and repaired as needed. If temp is now correct, replace the actuator. If my answer has helped you, please help me by leaving a rating using the stars at the top of this page or accept the answer so I may be credited. Rating or accepting my answer does not cost you extra. It allows me to be credited for my time. Please rate or accept. You can ask follow-up questions after you rate.
For an image location view of the actuator, click here:https://www.dropbox.com/s/a3eugn56jnfup2p/temp-act.jpg?dl=0