I have read in previous posts that when you first turn on the a/c on a 240D that the auxiliary fan comes on immediately. On my '82 240D it does come on but it takes probably about a minute or so. Is this a problem that needs to be taken care of.
BTW, I had my a/c retrofitted from r-12 freon to the r-134. This was after the compressor seized up. I had the compressor, drier, expansion valve replaced and everything flushed out. Being in Houston, you can't live with an a/c system so I had to quickly get this fixed because MB Tex doesn't feel too good against your legs when your wearing shorts and it is blistering outside with high humidity. The temperature difference from before and after is about 2 - 4 degrees warmer coming out of the vents. It's ok, but I wish it would be colder. If the temperature out of the vents was warmer after the conversion, I probably would have opted to try the new alternative refrigerants that are supposed to be colder than even the r-12. It appears that the a/c systems retrofits on the 123 body styles are marginal in performance.