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

Steering Wheel Components


Object Number: 1739392  Size: LF
(1)Heated Steering Wheel Control Module (KA9)
(2)Horn Switch
(3)Steering Wheel Control Switch Assembly - Right (UK3)
(4)Horn Switch
(5)Steering Wheel Control Switch Assembly - Left (K34/KA9)
Figure 2:

Horns


Object Number: 1750395  Size: LF
(1)Horn - Right (7Z1/YE9)
(2)Radiator Core Support
(3)Horn - Left