Ford 2006 F-250 Owner's Manual page 306

Accessories
theft alarms - that are equipped with radio transmitters. Any such
equipment installed in your vehicle should comply with FCC or CRTC
regulations and should be installed only by your authorized dealer.
• Mobile communications systems may harm the operation of your
vehicle, particularly if they are not properly designed for automotive
use.
• To avoid interference with other vehicle functions, such as anti-lock
braking systems, amateur radio users who install radios and antennas
onto their vehicle should not locate the Amateur Radio Antennas in
the area of the driver's side hood.
• Electrical or electronic accessories or components that are added to
the vehicle by the authorized dealer or the owner may adversely affect
battery performance and durability.
306
2006 F-250/350/450/550 (f23)
Owners Guide (post-2002-fmt)
USA (fus)