WARNING: This page is about a different car, the 2003 GMC Safari and 2003 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Air Conditioning System Performance Test Chart (Steps 1)
Courtesy of GENERAL MOTORS CORP.
Fig 2: Air Conditioning System Performance Test Chart (Steps 2-4)
Courtesy of GENERAL MOTORS CORP.
Fig 3: Air Conditioning System Performance Test Chart (Steps 5-8)