WHEN THE WEATHER STARTED TO GET COOLER I ATTEMPED TO PUT THE HEAT ON IN MY 2006 CHEVY EQUINOX AND NOTHING BUT COLD AIR CAME OUT! I WENT ONLINE AND FOUND OUT THAT THIS IS A COMMON PROBLEM WITH THIS MAKE AND MODEL. THIS IS A SAFTEY CONCER BECAUSE I ALSO HAVE NO DEFROST. THE LACK OF HEAT IS CAUSED BY THE AIR TEMPERATURE BLEND DOOR FAILING TO OPERATE. THE BLEND DOOR ALLOWS AIR TO FLOW PAST THE HEATER CORE. THE AIR TEMPERATURE DOOR HAS A PLASTIC ARM WHICH IS CONNECTED TO AN ELECTRIC MOTOR. IT SEEMS THE PROBLEM IS WITH THIS PLASTIC ARM BREAKING AND MOTOR MALFUNCTION. GM DEALERS REPLACE THE PLASTIC ARM WITH A METAL ARM AT A COST TO THE CONSUMER OF BETWEEN $1100 AND $1400 DOLLARS. THIS IS A MANUFACTURES PART PROBLEM. GM SHOULD STEP UP AND MAKE THIS PROBLEM A RECALL ISSUE. SAFTEY IS INVOLVED. THE NEWER MODELS HAVE BEEN MODIFIED FOR THIS SAME PROBLEM. *TT