I am trying to diagnose problem with cold air on driver side. It is colder on passenger side.

 

I don't think your problem is with the unit shown. The air that feeds out doesn't get separated like that. There was another thread talking about this and it mentioned that the air coming across the evap coil isn't cold enough and looses temp rapidly causing a Temp gradient. The person re-charged the air system with refriderant and it cured the problem