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

Horn Location


Object Number: 1416077  Size: SF
(1)Horn
Figure 2:

Steering Wheel Components


Object Number: 1825870  Size: LF
(1)Horn Switch
(2)Steering Wheel Control Switch - Right (UK3/K34)
(3)Steering Wheel Control Switch - Left (UK3/K34)