Did you have the smell before the blender door actuator fix already, or diid it occur after this? And with heater ****, you actually mean the mode selector? Or the temp selector?
Trying to chase a smell is even more difficult that a sound and almost impossible to advice on over the internet. We can't be there to smell it, so you will need to try and locate it further.
But if you select cabin air recycle and dont have the smell, than yes that would suggest i'ts coming in with the outside air...