Chirp in A/C vent

[lsu-sec]

Has anyone heard a high-pitched chirp sound coming from the A/C vent? (2001 Sierra)  It seems that if I turn the blower on high then down to 1 the noise goes away temporarily.

[95 Silverado]

in the older trucks it was usually the blower motor, they tend to chirp on low speed when the armature bushings get dry. Just put a new blower motor in the wife's '91 blazer for the same reason.

[SilveradoWV]

On my '02 Silverado I chirp when I have the AC on whenever I take off. Right when I ease up on the gas something will chirp under the hood, only when the AC is on. It doesnt worry me though since it only does it on the first take off.

[Stepside Z]

I would take it in and have the dealer look at it. My 99 Sserria did the same thing and they had to replace the blower motor.