VEHICLE NO LONGER BLOWS HOT AIR WHEN HEAT IS ON THEREFORE THE DEFROSTER WILL NOT BLOW HOT AIR AS WELL. THIS IS A SAFETY HAZARD! IF WINDOWS ARE FOGGED OR ICED DURING INCLEMENT WEATHER YOU CAN NOT SEE AND COULD CAUSE AN ACCIDENT RESULTING IN FATALITIES. I FOUND OVER 500 COMPLAINTS ABOUT THE SAME PROBLEM ON THE INTERNET. PROBLEM SEEMS TO BE WITH A PLASTIC TEMPERATURE DOOR VALVE (TEMPERATURE BLEND DOOR) THAT IS BROKEN. ACCORDING TO OTHER CUSTOMER COMPLAINTS AND THE SERVICE DEPT MANAGER AT OUR LOCAL GM DEALER, THE COST TO REPLACE THE FAULTY PART IS AROUND $1300 FOR $50-$80 METAL PART. FURTHERMORE, BY REPLACING THE PLASTIC PART PREVIOUSLY USED TO A METAL PART IN THE NEWER VEHICLES CLEARLY SUGGEST GM KNEW THERE WAS A PROBLEM WITH THE CRAPPY PLASTIC PART PREVIOUSLY INSTALLED. THIS IS A SAFETY HAZARD AND GM NEED TO STEP TO THE PLATE AND RECALL THIS ITEM BEFORE SOMEONE IS KILLED. MY WIFE ALREADY DAMAGED THE CAR AND TOOK OUT A MAILBOX DUE TO REDUCE VISIBILITY. *TR