Nissan Repair: A/C in 2001 Sentra XE, slow leak, condensor

Question
The A/C has always worked before and I thought I just needed a recharge.  Once I had coolant added, the A/C worked well for about a week, and is now back to blowing warm air.  We're taking it to our mechanic on Thursday, but I would like to know your opinion of what the possible problem might be.  

Thank you!  

Answer
TJ,

You probably have a slow leak.  The guys at the shop will fill it up and check for leaks with either a dye and a blacklight or a halon detector.  But, it is probably a hose or connection.  Now I have seen where the condensor has had a stone hit it and that could be the source too.  So, have them show you where it is leaking when they find it.