I just replaced the cabin filter in my 03' A4 Q with a charcoal charged filter. After installing the filter I noticed that when I drive the inside of the cabin is very warm and I have the environmental controls both at 65 degrees on auto.

The issue is the fan speed is always low unless I manuallyincrease thefan speed. Any ideas as to why this is happening. Thanks in advace.

 

Um......... try taking out the filter you intalled and see if it changes? I don't know what else to tell you, a cabin filter has nothing to do with changing interior temps.