I have a 2008 Impala LT sedan. Recently, when we run the air conditioning, the passenger side blows really cold air while the drivers side blows hot air. Adjusting the driver control changes nothing. When I have the key on, engine off, I can operate the controls for each blend door and can hear the doors moving back and forth with no clicking. I did replace the passenger side blend door actuator about a year or so ago, but it was clicking almost all the time. Just wondering if replacing the driver side blend door actuator is the fix or is there something else I should be checking out. Please help.