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

Horn Switch


Object Number: 1291221  Size: LF
(1)Turn Signal/Multifunction Switch
(2)Hazard Switch
(3)Horn Switch
(4)Steering Wheel Controls - Right
(5)Steering Wheel Controls - Left
(6)Data Link Connector (DLC)
(7)Headlamp Switch
Figure 2:

Horn Assembly


Object Number: 1336152  Size: LF
(1)Forward Lamp Harness
(2)Horn Assembly
(3)Horn Assembly Connector