I just bought a 2001 ford focus and there is a problem with the a/c. it comes on and runs for about 1 min then cuts itself off and the air it blows is not really cold. i checked the refrigerant and it is fine. the compressor seems to be working fine also. i noticed that the car has no cabin filter so i was thinking that the a/c coil may be dirty. i took the dash out but i cant figure out how to get the plastic box around the coil out of the car so i can check it. does any one know how to do this?