GM Service Manual Online
For 1990-2009 cars only
Figure 1:

Liftgate Harness


Object Number: 297999  Size: MF
(1)Rear Window Wiper Motor
(2)Rear Window Wiper/Washer Module
(3)Liftgate
(4)Rear Liftate Release Motor
Figure 2:

Liftgate Lock/Unlock Release Switch


Object Number: 297933  Size: MF
(1)Liftgate Lock/Unlock Release Switch
(2)Liftgate