I replaced blend door actuator in my 2012 Impala. Worked for 2 days then started clicking again but real fast, like rapid fire. Called Dorman (manufacturer) and asked for help. I was told that these actuators need to be calibrated and you also need to turn off climate control and disconnect battery before swapping out. If you don't do all that, the part thinks it's out of time and is ruined. I just ordered replacement part. If all this works, I'll update with better details on how to do this.