defroster makes BANG under dash?! Normal?
 

Hey all, like myname says, i have a 98 c5.

So my question is if this is normal or not... What ever setting i have the climate control on, when i hit the defroster buttom, there's a 2 second delay, then a loud BANG like the closing of a large plastic vent maybe?
with the music up, you even hear it bang. Sound like someone clapping on the outside of a window loudly.

That normal?!


ALSO... why does the A/C need to be on in order to use the front defroster? and sometimes it doesn't?

Lastly, is it normal for the rear defroster to completely make my radio go static?
When ever i have the radio on, and turn the defroster on, there's a 2 second delay, then something electrical makes my entire stereo go all snowy static. Turn the defroster off, and stereo goes back to normal.

ANY IDEAS?! Thanks.
~Kevin