Noise when Climate Control Fan is on...
 

The last couple days whenever I turn the fan on, it makes this rapid clicking noise. It sounds almost as if the fan was spinning and the blades were hitting something as they spin, something small because the noise is not incredibly loud.

Any ideas on what could be causing this? It's starting to become really annoying now.

Also, if the fan is on for a long period, the noise goes away but immediately comes back if i change fan speeds or turn it off and then on again.

Any feedback will be greatly appreciated.

ThanX.