Has anyone ever experienced their ac kicking on and off about every 5 seconds? I know the system is charged cause at times it will stay on and will blow nice and cold. But the majority of the time you can here the compressor kick on for a second and then off for a few. The car is developing a slight whirring whinning noise that is not affected by the ac switch being on or off and doesn't seem to be related to engine speed. it lasts for just a second more than the engine when you cut the engine off. Any idea?