Fiat 500L 2014 Owner's Manual page 414

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 in-
stalled 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 be-
tween the communications equipment and the vehicle' s electronic
systems.