-7-
wire that was cut in step a. Insulate the splice with
the wire nuts (supplied).
CAUTION
The horn ring transfer circuit of the siren is
capable of switching a maximum of 2-amperes.
Some vehicles do not have a horn relay and,
consequently, will draw more than 2-amperes
when the vehicle horn is activated. Consult
your vehicle service manual or a qualified
mechanic to determine the current required
to activate the horn. If it is less than
2-amperes, perform the procedure in step c.
If it is greater than 2-amperes, perform
steps d through j.
c.
Splice the white power cable wire
to the horn side of the cut wire. Insulate the splice
with a wire nut.
d.
Obtain a SPST relay of sufficient
contact current capacity to activate the vehicle horn.
Refer to figure 3-7 while performing the following
steps.
e.
Mount the relay in a suitable
location.
f.
Connect the horn side of the wire
cut in step a to the relay contact terminal.
g.
Determine the “sense” of the
vehicle’s horn ring activation circuit, i.e., does the
horn circuit require a switched positive voltage or
switched ground for activation.
h.
Connect the switched relay
contact terminal to the positive or negative potential
determined in step g.
i.
Connect the white power cable
wire to one end of the relay coil.
j.
Connect the other end of the relay
coil to the opposite potential of that connected to the
switched relay contact terminal in step h.
Figure 3-7. Horn Ring Connections.
290A3913-10
VEHICLE HORNS
STEERING COLUMN
TO BATTERY
RELAY (USER SUPPLIED)
CUT WIRE
SW
TO HORN, OR HORN RELAY
CONTROL CABLE ASSEMBLY
WHT
WHT/YEL TO HORN SWITCH
4.
Park-Siren Deactivator and Load
Manager Activation.
IMPORTANT
It is the installer's responsibility to determine
an appropriate location in the vehicle cir-
cuitry to connect the PARK (NEUTRAL
SAFETY) wire. This location should be
determined prior to installation.
This feature uses the park input wire
to enable the load manager and automatically
deactivate siren tones when the vehicle is shifted into
PARK.
See figure 3-6. To use this feature,
connect the power cable’s gray wire to a vehicle
circuit that is grounded when the vehicle is shifted
into PARK.
5.
Common Microphone Enable.
The control head's key #10 (the second
key from the left in the middle row) can be configured
for either common microphone control or high idle
control. Refer to Level 5-Load Management program-
ming in the Operation and Configuration Instruc-
tions to program the function of this key.
If common microphone control is
enabled, the control head's PA switch will function in
a push-on/push-off mode with a +12VDC (2A max.)
output to operate in conjunction with the common
microphone module and share the common micro-
phone with the Ericsson Orion™ radio.
The common microphone enable and
high idle control are mutually exclusive. See figure 3-
8 for driving an external device.
6.
High Idle Control.
Configure the high idle control as
described in the Operation and Configuration In-
structions. The control head's high idle switch can
function only in a push-on/push-off mode when the
vehicle is shifted into PARK.
When the vehicle is shifted into PARK
and the control head's high idle switch is activated,
+12VDC is supplied on the power cable’s violet wire.
This +12VDC is capable of supplying 1-amp., which
should be adequate for most high idle activators.
If an external relay to drive the high
idle activator is needed, a 40-amp. relay (Federal
Signal Part No. 131A175) is recommended. Figure 3-
8 shows the wiring for any single pole relay. The pin
