The noise you're hearing is most likely a chirping or high pitched squealing sound. You may find that simply lubricating the motor may solve the noise. This is a very simple DC motor and the shaft bearings are exposed at both ends. Once you remove the aspirator from the dash structure it's very easy to access the motor. A light weight oil should do the trick. I lubricated mine using a pinpoint oiler purchased from a hobby store.
I noticed that you have removed the a/c compressor and lines. Since the ATC system blends cool and warm air I wonder how well it will regulate the heat output without the a/c system operating.
I noticed that you have removed the a/c compressor and lines. Since the ATC system blends cool and warm air I wonder how well it will regulate the heat output without the a/c system operating.