Harris M7300 Installation And Product Safety Manual page 41

2. Obtain one of the waterproof (HFB type) fuse holders included with the DC Power Cable.
3. Observe and follow the previously presented WARNING!
4. Cut the red wire to the required length for connection to the battery's positive (+) battery terminal (or
the main DC bus bar or stud).
5. Prepare to splice the waterproof fuse holder into the red wire by cutting it again, at approximately
three (3) to six (6) inches from the end.
6. Strip all three (3) wire ends back approximately ⅜-inch, place a fuse holder shell on each wire, and
securely crimp a fuse holder terminal to each wire end. Before crimping, verify fuse holder shells are
oriented in the correct directions (i.e., with each large end towards the wire end).
7. Label this fuse holder and red wire appropriately (e.g., "M7300 Main Power: 15-AMP FUSE").
8. Do NOT install a fuse into the fuse holder at this time.
9. Crimp an appropriate electrical terminal to the short red wire. A corrosion-resistant ⅜-inch ring
terminal is included with the cable for this purpose, but another size corrosion-resistant terminal type
(not supplied) may be used if required.
10. Connect the ring terminal directly to the battery's positive post (or if present, to a stud on the battery's
main/non-switched power distribution terminal block).
A front-mount M7300 mobile radio installation may be equipped with additional CH-721
control heads in a multi-head installation. In this case, refer to Section 8.3 (begins on page
55) for control head installation procedures.
7.2.2.3 White Wire Connection
A review of the information presented in Section 7.2.1 (page 38) may be beneficial at this time. As
required per the chosen power-up configuration, connect the white wire by following one of the three
procedures presented in the respective sub-section that follows.
7.2.2.3.1 Radio Turns On and Off with Vehicle's Ignition Switch/Key
With this wiring configuration, the radio (and its control head) automatically turns on and off with the
vehicle's ignition switch/key. The white wire is sometimes referred to as the "white ignition switch wire"
or the "ignition sense input wire." 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 CH-721 control head's on/off/volume control must be left
in the on position for automatic power-up/down to function properly.
The white ignition sense wire must be connected to a fused power source that switches
from approximately zero volts to approximately +13.6 volts when the vehicle's ignition
switch/key is turned from the OFF position to the ACCESSORY and RUN positions.
Use of a switched power source that is subject to voltage changes as a result of other
actions, such as opening a vehicle door, may result in undesirable radio operation and/or
a degradation of radio performance.
1. Locate the vehicle's switched ignition or "Accessory" power connection point that will be used for
the switched ignition 12-volt DC power source. This point is typically located at or near the vehicle's
fuse panel. It may be necessary to consult the vehicle manufacturer's wiring diagram.
MM-014763-001, Rev. E
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