This started yesterday. Front is fine, but rear A/C is not blowing cold. I hear a whining sound in the rear like the coolant is trying to "spool up." I also noticed that the usual condensation drip around the exhaust area is not there. We are going on a road trip today and we are going to have to tough it out. Fortunately, this is the last hot day I think we will have. I am in between jobs and hope I can hold off until spring to fix it. Thanks in advance for the help!