Glad you got it fixed. The heat is getting unbearable, especially after I was out of it for two weeks, came back and it really hit me hard.
I think your aux fan is okay. I'm not positive about your model, but I think that you will find two pressure switches at the filter drier in the front passenger side of the engine compartment. One of them is low pressure to cut out compressor when there is an inadequate charge and the other is for the aux fan, which runs at high pressure. When the fan is turned on at a high pressure level, the extra air flow across the condensor will reduce the high side pressure.
Good luck, and we'll have to have lunch again soon,
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in