Whistle when the vent is on....

This problem should of been solved when I had the car under warrenty but its past and now I'm stuck with it. Its been like this since I bought the car. Everything works great except when you put on the fan for the vents there is a whistle in system. I tried to blow air in all the vents thinking its a leaf or something that got stuck in there, never helped. I know I don't have a cabin filter since its a 2003 Silverado. Its mainly comming by the fan itself, under the glove box, any suggestions on what to do? I really don't want to take the HVAC system appart to see whats going on. Thanks

nobody has the same the problem like me, I feel misplaced.

I have a whine when the fan is set on 3-4-5. I beleive it is the fan itself going out as my 2002 has 200+k miles. It should be just a couple bolts and a wiring plug to change it but i havent had the ambition nor the time to locate it and verify it. I have been told you can spray either silicone or graphite lubricant on it to prolong the life of the fan, but I would check with someone before trying that. Good luck and let me know what you come up with.

my 2004 did it striate from the factory. so far there is no fix other than rolling down the window. Chevy put vents in the back of the cab to stop the negative air pressure, then coved them up with the matting behind the seat.

my 04 does the same thing on the higher settings and it only has 30k miles on it. I havent really looked into fixing it and just keep it on setting 1 or 2 most of the time.

Mine has only 26K, too bad I can't take in though. They'll probably charge me for looking at it. But I'm going to ask them about it when I bring it in for my Cluster Recall. Friggin 26K and the needles are all messed up. I love Chevy but why must they buy crappy clusters.