I just bought a 2001 C320 yesterday. Problem I am having is with the A/C system. When I turn the A/C on, I see that A/C compressor kicks in but I get no cold air in the cabin also, there is this button which says" A/C OFF" on it. It lights up. How can I diagnose this problem, or what could be wrong with it? There is freon in the system and no leaks at all. Any ideas and help will be appreciated.