First... I have blocked off my front hubs w/ a rubber boot. I turn my truck on and sometimes it blows out the face (where i left it) and sometimes out the defrost (which I understand is the default mode). If it comes out the defrost I can turn the A/C off and then back on and it will come out the face. Any other mode ex floor it will blow out the defrost. Not sure if this has anything to do with it but all the above is when it is set at 60 degrees. If I increase the temp to 70 degrees sometimes I can get all the buttons work perfectly fine. Hit floor it goes to floor, face goes to face ect. I know it sounds weird but any help would be greatly appreciated. BTW I have taken the rubber cap off the line and checked it with someone holding their finger over the and it does the same thing so I know its not there at the box. Thanks again.