2005 A4 3.0 Quattro Problem: Driving today back home (about 480 miles), kept getting hotter and more humid, ac working fine, all of a sudden it stops working, i.e. blowing cold-starts blowing warm air, but not as hot as outside, so still a little cool coming out.....I'm thinking, freon low...finally get to destination, pop hood, there's ice all around my a/c tubes going into condenser behind firewall...put my freon tester on, 45 lbs (which is normal and perfect)....broke the ice off....let it sit for awhile, huge puddle under car. almost running down driveway.....start her up, A/C working fine again??

Now, I'm wondering, trying to be logical....could my drain plugs be clogged? Reason for this assumption: yesterday, huge rain and hail storm, drove through it and it dumped about a foot of rain in 10 minutes (exaggeration), but you get the drift....never checked...but, could standing water have been left in my engine compartment by the battery, evaporated on the trip today, but was still there this morning, but somehow made my coil freeze up?

Or is there a sensor somewhere that cycles the A/C that could be bad?

Thanks guys...
Marky

 

Just scanned it and checked blocks for vents, all ok, no codes. AC is currently working good. Worked fine 2 days ago on the 480 mile trip there......it was the low pressure line coming out of the evaporator that has ice on it....evaporator on the outside didn't seem frozen, just really cold.....