Air conditioning

[onlyav6]

Both switches I replaced, I did not replace anything with the vacuum. Could this peice be bad.
From the off position when you flip the blower switch on it comes on when I go all the way to each section Max normal by level stays the same until I go up to defrost then the blower motor turns off.

 

[corsair231]

A/c is not my strong suit but on GM vehicles, when you turn the defrost on the a/c compressor is supposed to come on as well. It may be something in your wiring or relays under the hood and not in the dash.