GMC Yukon 2021 Owner's Manual page 308

Warning
Certain mobile radio equipment,
like amplifiers and antennas used for
two-way communication, can interfere
with some vehicle systems. Always
ensure this equipment is supplied with
proper local grounding. Follow all of the
instructions that came with the
equipment and see your GM dealer for
additional mobile radio installation
instructions.
Add-on equipment can drain the vehicle's
12-volt battery, even if the vehicle is not
operating.
The vehicle has an airbag system. Before
attempting to add anything electrical to the
vehicle, see Servicing the Airbag-Equipped
Vehicle 0 69 and
Adding Equipment to the Airbag-Equipped
Vehicle 0 70.
Driving and Operating 307