newbraunfelsgmc

This may not have anything to do with the post , but i did notice on my 2014 sierra that if i put button too circulate the inside air, ie hit recirc button, AND the air was set to blow from the bottom, ie button showing air going to the feet, i would still get outside air coming in. I noticed this not from the smell so much, but since it is cold outside, and i have the temp to hi, warm air was still coming into the cab. If i switched it to air coming from vents, ie button showing air coming to the upper body, no air came in. I could tell cause i could no longer feel warm air and the cabin would get cold, or vise versa, depending on the temp setting. I really don't know why this is happening, or if it related somehow. i just know that on my previous vehicle, a toyota sequoia, if i hit the recirc button, absolutely no air, hot or cold, or smell for that matter, would enter the cabin.