WARNING: This page is about a different car, the 2006 GMC Sierra and 2006 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Cruise Control Schematic - 4.3L
Courtesy of GENERAL MOTORS CORP.
Fig 2: Cruise Control Schematic - 4.8L, 5.3L, 6.0L, and 8.1L