I'm sure this is not the first time this subject has been brought up but my 2002 c-230 blows cold air on the passenger side and hot air on the driver side. Any experience out there for tips causes and solutions?

 

I had this exact issue it was an issue with a motor/linkage that controls the air mixture. you can get to this motor and linkage through the carpet to the right of the throttle pedal do a search for the stepper motor locations. I took mine apart and it immediately started working again and that was two years ago.