Installation Manual

Table Of Contents
14221-1850-4000, Rev. A
31
Any DC input power provided to the radio must not be
13.6 volts DC ±10%.
conditioning is required before any DC power is connected to the radio. This includes
conditioning for both the radio’s main DC power input lead and for its switched ignition
sense power input.
DC conditioning can be accomplished by a noise filter or DC isolation equipment such as
Harris part number FL-018314-001 or FL-018314-002 for non-TDMA operations, or
filters for TDMA operation with similar current draw specifications. A fuse must be
6.3.3.1 Power On/Off Using Vehicle Ignition
For the mobile radio to be powered on and off with the vehicle’s ignition, the sense wire needs to be
connected to one of switched power sources, typically known as accessory power.
In this configuration, the white wire connects to a switched power source, typically identified as
“Accessory” power, that switches on and off with the vehicle’s ignition switch/key. When using this
configuration, the Control Head’s on/off/volume control must be left in the on position for automatic
power-up to function properly.
The accessory source is normally found in the vehicle’s interior fuse block. The source chosen should have
nothing to do with the vehicle’s safety systems. Refer to the vehicle’s owner manual when choosing an
appropriate accessory source.
6.3.3.2 Power On/Off Using Master Power Switch or Timer
In this configuration, the ignition sense wire is connected to a 12 VDC power source with a master switch
or a timer in-line. Typically, the 12 VDC source is the same as the mobile or Control Heads power source.
Master switch install - This allows the radio to remain powered on after the ignition is turned off. It is
important to note that the vehicle’s battery will go dead if the switch is not powered off.
Timer circuit install - This allows the radio to be powered on for a set time. This configuration can also
drain the battery if it is weak or old.
6.3.3.3 Power On/Off Using Mobile Radio On/Off/Volume Control Knob
In this configuration, the ignition sense line is connected directly to a 12 VDC power source. The 3-amp
fuse must be installed in-line. The mobile is powered on and off with the Control Head’s on/off/volume
control knob. The vehicle’s battery will go dead if the vehicle is not running. Review the above mentioned
quiescent current draw when ignition is on and the control head on/off knob is in off position.
6.3.4 Ground/Return Location and Considerations
Ensure the location chosen is truly to vehicle ground.
The location chosen should not be in an area that is prone to moisture retention.
Ensure that the location will protect the terminal from being bumped and allow the connection to loosen.
The location must allow a through bolt with a nut and lock washer or be at a factory ground.
Choose a location that will allow the ground lead to be as short as possible.
6.3.5 Antenna Mounting Considerations
Choose the antenna location based on the installation instructions provided in this manual and in
consideration of other items installed on the vehicle’s roof.