GM Service Manual Online
For 1990-2009 cars only

The horns are bolted to the body at the forward portion of the front wheel opening. The A-note horn and the F-note horn are located on the right side of the vehicle. Vehicles equipped with a 3-note horn system will have a D-note horn on the left side of the vehicle. The horns sound when the steering wheel pad is depressed. This action grounds the horn electrical circuit.