Turn wheel right and AC blows hot

Hey everyone - got a strange one:

When I turn the wheel to a hard right, there is a clicking noise and the air conditioning starts to blow HOT air.  The clicking noise happens off and on, not only when you turn.  It keeps blowing hot air until you turn the wheel HARD left.  

Now, after a year of this, there is only hot air blowing.

Any suggestions on where to begin?

Thanks!

ohmzoned@gmail.com