DEFROSTER- IF YOU TRY TO DEFROST AND SET THE TEMP TO 74 DEGREES OR BELOW IT ONLY BLOWS COLD AIR- 75-76 DEGREES IT BARELY BLOWS WARM AIR-- BUT NOT ENOUGHT TO REMOVE ICE/ SNOW OR FROST. IF YOU SET THE TEMP TO 77 IT BLOWS 152 DEGREES.. IT WAS MEASURED AND THAT IS THE TRUE TEMP 152. THIS IS VERY DANGEROUS. YOU EITHER CAN'T GET THE WINDSHIELD CLEAR OR CLEAN OR YOU ARE ABOUT TO DIE OF A HEAT STROKE. I ALSO BELIEVE IT IS BAD FOR THE WINDSHEILD TO HAVE 152 DEGREES ON THE INSIDE OF THE WINDSHIELD AND 32 DEGREES OR BELOW ON THE OUTSIDE... THE DEALER IS VERY GOOD AND TRYING TO FIND A SOLUTION BUT HAS NOT BEEN ABLE TO YET. OUR TECH SAW AND FELT THE 152 DEGREES. THEY ARE GOING TO CONTACT GM FOR A SOLUTION. THIS IS A HUGH PROBLEM AND HERE WE ARE GETTING INTO THE BAD COLD PART OF WINTER. I SHOULD ALSO MENTION THAT IT WILL NOT DEHUMIDIFY EITHER SO THE WINDSHIELD IS FOGGED UP... ALSO VERY DANGEROUS. DOES ANYONE ELSE HAVE THIS PROBLEM WITH THEIR TERRIAN OR GMC.

Update from Dec 16, 2015: my husband found a solution. hit the auto button then hit the next button to the right ( it is a man that shows the air coming out of the top arrow) it has 4 setting and 1 is the defroster symbol. the temperature setting then works the way it should and the dehumidify works there also.. the button that has the defroster sign is only for quick melting of ice or snow, hence the 152 degrees. we shared this with the dealer so they would know this for the next time. hope this helps others. thanks for letting me post this