The label on the forward light electrical centre may have the positions of the horn and fog lamp relays reversed (see illustration). Some obsolete labels were used in production. These labels are in vehicles from VINs MD349157 thru MD349624. The wiring shown in the Service Manual is correct.
The forward light electrical centre is located under the hood, on the right hand frame rail, under the large electrical centre, and in front of the ECM. The coolant overflow reservoir may have to be removed to gain access to the centre.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.