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

Horn Conponent Location


Object Number: 587206  Size: LF
(1)Horns
(2)Horn Connectors
Figure 2:

Steering Wheel


Object Number: 587205  Size: LF
(1)Horn Spring Opening
(2)Inflator Restraint Steering Wheel Moduel
(3)Horn Switch Spring Loaded Contact