2003 C240 4Matic AC problem

[Alibaba007]

I have recently purchased this 2003 C240, and i notice that when the AC is turned on, the driver side is very weak, as if the fan is just blowing and the passenger side is much colder, but not as cold as it should be. Has anyone had this problem? or perhaphs have a good idea as to what is causing the problem? Thank You much!

AL