WARNING: This page is about a different car, the 1995 Pontiac Trans Sport and 1995 Chevrolet Lumina APV. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Wiring Diagram (Lumina Van & Trans Sport - 3.1L - 1 Of 2)
Fig 2: Wiring Diagram (Lumina Van & Trans Sport - 3.1L - 2 Of 2)