HVAC noise

[subforry]

Now that I have a working HVAC blower, I'm getting noise when I run the blower. I thought it was a vacuum leak but I disconnected the hoses at the HVAC push buttons and it still make the noise. It seems to change when I switch to AC or heat or defrost. Is there some other electro/mechanical device in the HVAC? Is this some kind of noise created by the air flow? Any ideas are welcome.

BTW: when I run the AC, a thing (solenoid?) on the right fender makes lots of noise. There is no AC compressor.

Thanks.