Federal Signal Corporation PA300 Series 690009 Installation And Operating Instructions Manual page 8

VEHICLE HORNS
RELAY (USER SUPPLIED)
SW
TO HORN, OR HORN RELAY
WHT
CONTROL CABLE ASSEMBLY
Figure 3-4. Horn Ring Connections.
3. Splice the white control cable wire (pin
5) to the horn side of the cut wire. Insulate the splice
with a user-supplied wire nut.
4. Obtain a SPST relay of sufficient
contact current capacity to activate the vehicle horn.
Refer to figure 3-4 while performing the following
steps.
5. Mount the relay in a suitable location.
6. Connect the horn side of the wire cut
in step 1 to the relay contact terminal.
7. 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.
8. Connect the relay wiper terminal to
the positive or negative potential determined in step
7.
9. Connect the white control cable wire to
one end of the relay coil.
10. Connect the other end of the relay coil
to the opposite potential of that connected to the
wiper in step 8.
D. Connection to Power Source.
CAUTION
Damage to unit will occur if not properly
fused. Ensure that an in-line fuse (20A) and
fuseholder are installed in the red power
cable lead for the 690010. A chassis mounted
fuseholder is mounted on the 690009—ensure
that a 10-ampere fuse is installed.
The PA300 Series can operate only from a
negative ground vehicle electrical system. Therefore,
before making any electrical connections, determine
the polarity of the vehicle electrical system ground.
STEERING COLUMN
TO BATTERY
CUT WIRE
WHT/YEL TO HORN SWITCH
290A4507-05
Power for the siren can be obtained from
the vehicle's power distribution center or directly
from the vehicle battery. If power is going to be
obtained directly from the vehicle battery, drill a hole
in the vehicle firewall for the power lead to enter the
engine compartment. Place a grommet or similar
device in the hole to protect the wire against damage
from rough edges.
Before drilling holes in ANY part of the
vehicle, ensure that both sides of the surface
are clear of parts that could be damaged; such
as brake lines, fuel lines, electrical wiring or
other vital parts.
If your vehicle has a negative ground
electrical system, perform the procedure as follows:
This unit is NOT designed to operate with
positive ground.
1. Route the red power (+) and the black
power (-) control cable leads, through the previously
drilled hole, into the engine compartment. Route the
wires through existing clamps and holders toward
the battery.
2. To protect the red wire when con-
nected to the battery terminal, use an in-line
fuseholder and appropriate (10-ampere for 690009
and 20-ampere for 690010) user-supplied fuse. The
fuseholder should be installed as close as practical to
the battery. If necessary, additional #14 gauge or
heavier wire can be spliced to the red lead.
If wires are shorted to the vehicle frame
or each other, high current conductors
can cause hazardous sparks resulting in
electrical fires and molten metal.
Verify that no short circuits exist before
connecting to the Positive (+) battery
terminal.
DO NOT connect this system to the
vehicle battery until ALL other electri-
cal connections are made and mounting
of all components is complete.
Failure to observe this WARNING will
result in fire, burns and blindness.
-6-
CAUTION
NOTE
WARNING