WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Power, Ground & Blower Controls Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 2: Compressor Controls & Serial Data Schematic (L26)
Courtesy of GENERAL MOTORS CORP.
Fig 3: Compressor Controls & Serial Data Schematic (LY7)
Courtesy of GENERAL MOTORS CORP.
Fig 4: Air Temperature & Sunload Sensors Schematic
Courtesy of GENERAL MOTORS CORP.
Fig 5: Air Delivery/Temperature Controls Schematic