Howling noise and no MAX from A/C

[hybrid_malibu]

I am running a 03 with some strange problems. I cannot use the MAX feature because the output is from the defrost vents only. And at about 15-25 mph it howls. Anyone have any idea's?

 

[ljr8378]

A/C Howling

I have a similiar problem. After about 1 hour with the AC on, it will begin to blow through the defrost. I brought it to the dealer (after I had driven it an hour and had it "howling") and he poped out the glove box and it stopped howling. So he said he could not fix the problem I was hoping to find someone who had a similiar problem and came up with a fix.

2004 XLT

 

[007]

Mine howls once in a while, but only when accelerating from a stop. If I back off the gas, the howling stops or decreases in pitch. If I jump back on the gas, howling comes back. Either way, it stops howling after a few seconds.

I'm thinking it's a vacuum line problem with the dampers.

My A/C works 100%, so I'm not awefully concerned.