Hey Guys, I have a 2004 Chevy 1500 Silverado. And i have been having this problem where my A/C only works when its on the highest setting... When i turn the air on from "0" to "1, 2, 3, or 4" it sounds like its engaging but nothing blows out the vents. Only blows out when i turn it to "5." I have no idea what the problem could be. Please help me out... Thanks.