hello there: I got the similar problem in my 2003 H2. When I turned on the A/C it sounds louder than usuall and it does not blows really strong. I take of all the screws from the down dash of the passinger side, remove the blower motor (is kind of hard but you can do it) got into the A/C outlet and hardly I realized the radiator or avaporator I guess was all stucked with dust, sand and leaves, etc, etc,... This causes that the blower motor can not blows all the way and make the air flows into the cabin, caussing that noise. It is a bit difficult to clean but it can cost you nothing if you are patient and know to use your vacum cleaner. I first try to revome all I can with my hand and a little tooth brush and then I used the vacumm cleaner with a little hose on it. The vacum cleaner one is to big to get into. I removed almos the 100% of the dust and now the A/C freezes all the way down.
Hope I helped.