A few weeks ago I had to drive through a snowstorm to get my son to college. It wasn't terrible, the roads were plowed, and I made it alright, but about 100 miles into the trip I stopped and found the front of my truck was accumulating snow, and partially blocking the grill. I also noticed the truck was running hot. Not overheating but maybe 15 degrees warmer than usual. When I stopped I discovered snow was accumulating on the front of the truck. It was inches deep and more ice than snow in some places. But the real surprise was looking into the grill, the radiator was covered in the same snow/ice mix. You would think the heat from the radiator would just melt this, but because the 1st radiator is the A/C radiator, it was remaining solid and building.

I was able to knock the snow off the front of the car, but could not get to the radiator, and would have been afraid to attack it with tools like I did on the front. Once home it melted in my garage.

 

I would have thought if you have defrost on, a/c would engauge and warm coils would melt the snow. Is your a/c compressor working??