I just had a climate control,compresseor,receiver drier,and expansion valve replaced. When I picked it up it 30 degrees outside. My mechanic showed me that it turned on by pointing out the compresser going. It has now warmed up (Texas) and when I turn it on it does not feel like real AC. I wanted to know if how the AC controls work does the outside ambient tempature matter?The Air does not feel any colder when it is on than when I turn the fan on with the EC button pushed. Do I still need something looked at? Once all those things are replaced what do you do next?
Can the AC be fixed but something else still needs to be done? So many questions for a rookie MB owner who just bought for the first time 3 months ago.

I think the most common problem causing this would be insufficient refrigerant in the system. Take the car back and have him look at the pressure (which is the indication of the amount of refrigerant in the system), and everything else he worked on for that matter. You shouldn't have this problem if he replaced everything he said he did .

You might want to do a search from last summer. A/C is always a big topic and I know people talked about the proper pressure. Also might want to check to make sure your fresh air intake is completely closing. If not, then it is allowing too much hot outside air in and not letting the A/C system do its job.

Good Luck,

Greg

How do you check if the fresh air intake is closing?

Hi Stephen:
have you checked the monovalve? It's located on the firewall in the engine compartment on the passengers side. Make sure the electrical connection on its top is tight and clean. Maybe you need just a repair kit.
my '85 300TDT needs one about every 3-4 years.