1987 Z28 V8 w/4 bbl carb...I know the a/c compressor comes on for "Max" "Norm" "Bi-Level" and "Defrost." I also know the idle solenoid increases the idle speed and the radiator fan comes on for the 3 a/c settings. I just noticed that for the "Defrost" setting, only the compressor comes on. I don't get increased idle and the radiator fan does not come on. I don't think that's normal. I think "Defrost" should work the same as the other 3 a/c settings. Any ideas?