Help please! Over the past year my 2008 mustang v6 has been making a loud clicking noise when I start my car or change the air conditioner setting in the center of my dash. But as of last night my air conditioner heater is stuck on defrost. If anyone can please tell me how to fix this myself to avoid getting ripped off at ford dealership I would greatly appreciate. I feel like it could be a hose or something of that sort. But pleas if you have had this problem and fixed it help me out.