Inserting The Radio Into The Mounting Bracket; Remote-Mount Radio's Dc Power Installation; Overview Of On/Off Power Wiring Configurations - Harris M7300 Installation And Product Safety Manual

MM-014763-001, Rev. E
8.1.2

Inserting the Radio into the Mounting Bracket

The radio should now be inserted into the bracket according to this procedure:
1. Lay the radio down into the mounting bracket with the front of the radio at the front of the mounting
bracket.
2. Attach the radio into the mounting bracket using the six (6) M5 x 10 mm stainless-steel socket-head
screws, and flatwashers and lockwashers included with the Mounting Bracket Kit (item 1 in Table
4-4). Tighten all six screws using a 4-millimeter hex key wrench until each lockwasher is fully
compressed and the radio is firm and flush in between the brackets.
3. Check the mounting area for proper clearance for cable service looping and for air circulation, plus an
area to secure and stow the excess cable lengths.
8.2

REMOTE-MOUNT RADIO'S DC POWER INSTALLATION

8.2.1

Overview of On/Off Power Wiring Configurations

Radio on/off power control is accomplished by the control head, except in the case of a data-only radio
installation which has no control head. In a standard installation, when the control head is turned on, it
"wakes-up" the radio via data activity on the CAN link. The following power wiring configurations are
supported:

Radio turns on and off automatically with vehicle's ignition switch/key — This configuration
allows the on/off state of the vehicle's ignition switch/key to control the on/off power state of the
radio. The white wire of the control head's DC Power Cable is connected to a fused switched power
source, typically identified as vehicle "Accessory" power. This source must switch on (up to positive
(+) battery voltage potential) when the vehicle's ignition switch/key turns on, and it must switch off
(to near zero volts) when the ignition switch/key turns off. The required fuse rating is 3 amperes.
When using this configuration, the CH-721 control head's on/off/volume control must be left in the
on position for automatic power-up/down to function properly.

Radio turns on and off with a manual switch — This configuration is used when, for example, the
radio must remain on even when the ignition key must be removed from the vehicle and a separate
on/off switch is acceptable. The white wire of the control head's DC Power Cable is connected to one
side of a manually-controlled switch, and the other side of this switch is connected to unswitched and
fused vehicle power. The required fuse rating is 3 amperes. When using this configuration, the
CH-721 control head's on/off/volume control must be left in the on position for automatic power-
up/down to function properly.

Radio turns on with control head's on/off/volume control ("hot wired") — This configuration
allows radio on/off power control only via the control head's on/off/volume control. It may be desired
if, for example, the radio must remain on even when the ignition key must be removed from the
vehicle and a separate on/off switch is not desired and/or not acceptable. The white wire of the
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Proper mounting is one factor that ensures optimal radio performance. An improperly
mounted radio may experience degradation in the quality of voice and data
communications.
In a remote-mount radio installation, to fuse the white wire of the control head's DC
Power Cable, a waterproof (HFB type) fuse holder and a 3-amp AGC fuse are included
with the cable.