RAM Ram Dodge 2009, Owner'S Manual, Page: 542 / 543

INSTALLATION OF RADIO TRANSMITTING
EQUIPMENT
Special design considerations are incorporated into this
vehicle’s electronic system to provide immunity to radio
frequency signals. Mobile two-way radios and telephone
equipment must be installed properly by trained person-
nel. The following must be observed during installation.
The positive power connection should be made directly
to the battery and fused as close to the battery as possible.
The negative power connection should be made to body
sheet metal adjacent to the negative battery connection.
This connection should not be fused.
Antennas for two-way radios should be mounted on the
roof or the rear area of the vehicle. Care should be used
in mounting antennas with magnet bases. Magnets may
affect the accuracy or operation of the compass on
vehicles so equipped.
The antenna cable should be as short as practical and
routed away from the vehicle wiring when possible. Use
only fully shielded coaxial cable.
Carefully match the antenna and cable to the radio to
ensure a low Standing Wave Ratio (SWR).
Mobile radio equipment with output power greater than
normal may require special precautions.
All installations should be checked for possible interfer-
ence between the communications equipment and the
vehicle’s electronic systems.