My 04 Deville had a clicking noise that drives you crazy and makes your feet cold and the rest hot. This fixed a confused air conditioner going through various vents and eventually settling on my legs. I was sweating above the waist and lost feeling in my toes from frostbite. Initially I disabled the drive so air was only blown through the forward facing vents which work fine but needed the defroster in winter so had to replace it with a new drive.