Check under the dash if ice is forming. I had the same problem. I got a letter from the dealer that invited me for a 'free airco check'. I knew I was low on refrignant.
I told them about the ice forming under the dashboard. They didn't knew what it was and they had to do a search through the whole car if I wanted to know what it was....
$$$$.
The check took 10 minutes and they told me something was wrong. I had to make a new appointment for next week so they could get in an 'airco specialist'. This told them that the evaperator was leaking. The strange thing was that when I handed the car over to the dealer, the A/C worked a little bit. When I got it back after 4 hours it was totaly dead
. Replacement would cost EUR.895,- -> $1,100.00.
I had a strange feeling about this so I called a real airco specialist. They told me that it's impossible to state that the evaperator was leaking without getting the dash out and put dye in the system
. They put the whole system under pressure, no leaks. Filled the system with 960 grams R134a and the A/C is real cold now. AND !!! No more melting ice on the passenger side. Total cost: EUR.140,- -> $170.00
So if you also know that you're low on refrignant, mebey this is the case
Dennis