On this picture, the circled component is leaking. What is it? It is attached.

 

I think the name is Receiver/Dryer for the AC system. It is for the AC System and it does get covered in moisture when the system is running. If it is leaking, it wouldn't leak long and all your "freon" would be gone - leaving your AC system to blow warm air. You may just be seeing the condensation while it is working...I have seen one covered in a thin layer of ice as well!

 

if it's dripping water, it's normal. if it's leaking freon, and you KNOW it's freon, then your a/c is screwed and it's mucho dinero to replace. as it's not quite DIY job. sorry and best luck.

 

http://reviews.ebay.com/Automobile-A...00000000932328

 

If your A/C is still going strong, don't worry about it. It's just condensation from your a/c unit.