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

Liftgate Strut Switch Wiring


Object Number: 374533  Size: LF
(1)LH Liftgate Strut Switch Connector
(2)LH Liftgate Strut Switch
(3)Liftgate Lock/Unlock Relay
(4)S334
(5)S335
Figure 2:

Right Rear Body Wiring


Object Number: 374539  Size: SF
(1)S334
(2)S335
(3)Liftgate Lock/Unlock Relay
(4)Liftgate Lock/Unlock Relay Connector