[jasin1]

I believe as others have said that the seam discoloration is from underneath but the actual accumulation of dirt on the one area could be from where it’s parked with wind blowing over the trailer and getting stopped by the ac unit and vent being so close in proximity to each other…or like I said earlier airflow going around and over the fan and ac shroud acting like an air foil

From the crickets response I’m assuming you all politely think I’m just crazy lol