Has anyone had to change out any of their hvac control actuators ie.(cold/hot & outside/inside air)? When I change from hot to cold there is a clicking noise behind the middle of the dash. My wifes Chevy Trailblazer had the same problem and it was somewhat easy to replace depending on which actuator motor it was. Gears inside are made of plastic. If it is easy to get to I would like to change it before it breaks in the middle of winter.