WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Diagnostic System Check - HVAC Compressor Clutch Does Not Engage (Step 1-12)
Courtesy of GENERAL MOTORS CORP.
Fig 2: Diagnostic System Check - HVAC Compressor Clutch Does Not Engage (Step 13-27)