Winding Noise in the AC
 

Hey guys. So my AC is currently working perfectly however I've noticed a winding noise associated with it. I suppose you could describe it as a faint version of the sound a poker card makes when clicking on a bicycle wheel. The sound stops when the AC is turned off.

Are these indications of something to come? Any initial ideas before I dig a little further?

Thanks

AC fan, below the dash, has trash or leaves in it. Drops down with three bolts. Careful, it is several hundred bucks. Some guys have had straw, rodent nests, etc. Sound would be speed related to fan setting.