Weird Buzzing Sound

[bizzy]

WHenever I have my heat or AC on I get this buzzing sound that comes from the passenger side front vent. Any idea on how I can get rid of this annoying sound? The heat and AC work fine so it is not causing any problem other than the annoyance.

 

[shamaal]

If it changes in pitch as you turn the speed up or down, then you have a leaf caught in the blower fan. Run it till the leaf wears down or pull the blower fan off and clean it out.

 

[sapacif]

Do you access the blower fan from the passenger compartment or from under the hood? Thanks.