WARNING: This page is about a different car, the 2002 GMC Safari and 2002 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Identifying Auxiliary Power Outlet - Front No. 1 Connector Terminals
Courtesy of GENERAL MOTORS CORP.
Fig 2: Identifying Auxiliary Power Outlet - Front No. 2 Connector Terminals
Courtesy of GENERAL MOTORS CORP.
Fig 3: Identifying Auxiliary Power Outlet - Rear Connector Terminals