Purchase a new 2012 GMC Sierra sle on 07/26/12. As I leave for work in the early hours, it requires that I use the defog/defrost. On the morning of the 28th I selected the defog/defrost and only the driver's side cleared. Thinking it may be isolated, I received the same result on the 29th. I called the selling dealer about another matter and mentioned this problem. On August 9th the truck was taken for service and to address this issue. Was told that it is operating as normal and the dealer tested two other new trucks. Still not happy with the answer, I called GMC. They setup service at another dealership for the 16th. Again, no problems could be found per their testing, but were going to change the duct as the air flow was much greater to the driver's side. When the duct came in, they opted not to change it, as it requires to strip the dash to the windshield. All this time GMC was updated of the progress. The system doesn't clear the passenger side of the windshield and passenger door window. GMC stand is, that engineering design the system this way to clear the driver's side quicker during poor weather, as like snow and ice. My stand is that this is not a proper answer for a vehicle maker to state. This issue makes the vehicle unsafe to operate and I do not live within an area seeing this type of weather often. I have read many internet articles related to this. Other owners trucks operate properly clearing both sides or have had them properly repaired if they have had the same issue. I need to have my vehicle repaired so that it can be operated safely. GMC will not admit that this is a problem requiring repairs.

- Hamilton, GA, USA