I just got back from a 60-day trip and turned on my 2004 Escalade ESV and the heat in the front did not work (i.e. no air (cold or hot) came from the front vents including front windshield). The rear vents did work properly. What is the potential problem?
These vents are generally operated by vacuum from the engine that is directed through the selector valve on your dash. Have your selector valve checked for a loose, or bad vacuum hose .