2009 Dodge Journey Owner's Manual - Page 522

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 personnel. 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 interference between the communications equipment and the vehicle's electronic systems.