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5
INTERCOM WIRING CHECK OUT
System Setup:
Before you connect the vehicle’s radios, check out the system oper-
ation. Do the following without the vehicle’s engine running:
First plug all headsets into the respective headset jacks. Put on one
of the headsets and position the boom mic close to the mouth, as is
the practice with hand-held microphones. Voice clarity is best when
the mic is about 1/4 inch away and slightly off center from the lips.
Turn the volume control on the headset, all the way up (clockwise).
On the UltraSound unit, set both the intercom VOLUME control and
SQUELCH control to full clockwise position.
Now turn vehicle power on. Verify that you can now hear yourself
in your headset. Verify also that you can hear all the other headsets
and that they can hear you. If everything is OK, skip to the “PTT
Test” section. Otherwise, if something is not working right, see the
following troubleshooting guide to find and fix the problem before
going on with the installation:
NO INTERCOM IN ANY OF THE HEADSETS:
1. Make sure the UltraSound VOLUME and SQUELCH controls are
set to full clockwise position.
2. Make sure the vehicle power is on.
3. Check the in-line fuse in the UltraSound Headset Jack and PTT
switch Cable.
4. Check the power connection – red wire.
5. Check the ground connection – green wire.
6. Check for a short or open on the headphone wire (Blue wire on
the Headset Jack and PTT Switch Cable). The problem could be
anywhere along the blue wire connection between the headset
jacks and the UltraSound unit.
INTERCOM IN SOME HEADSETS BUT NOT IN OTHERS:
1. Make sure that UltraSound controls are set as above.
TIP
BARREL
RING
HEADSET JACK
OFFICER
TIP
BARREL
RING
HEADSET JACK
DRIVER
TIP
BARREL
RING
HEADSET JACK
CREW #1
TIP
BARREL
RING
HEADSET JACK
PUMP PANEL
RADIO #2 PTT SWITCH
(J1-5) ORANGE
RADIO #1 PTT SWITCH
(J1-2) WHITE / RED
RADIO #2 PTT SWITCH
(J1-6) WHITE / GREEN
RADIO #1 PTT SWITCH
(J1-10) WHITE / BLUE
RADIO #2 PTT SWITCH
RADIO #1 PTT SWITCH
(J1-6) WHITE / GREEN
(J1-10) WHITE / BLUE
(J1-7) RED
(J1-12) GREEN
(J1-1) WHITE / BLACK
(J1-11) WHITE / ORANGE
(J1-8) TAN
(J1-3) BLUE
(J1-4) BLACK
(J1-11) WHITE / ORANGE
P1
J1
+11 to +16
VOLTS DC
FUSE
(1 AMP)
CHASSIS
GROUND
US-LAC4
WIRING DIAGRAM
Figure 4
INTERCOM UNIT
123.00
RADIO 1
SPEAKER HI
(J2-2) VIOLET
NOTE 1
SPEAKER LO (J2-3) VIOLET
NOTE 1
PTT HI
(J2-5) WHITE
NOTE 2
MIC LO
(J2-4) BLACK
MIC HI
(J2-1) BROWN
PTT LO
(J2-6) WHITE
NOTE 2
123.00
RADIO 2
SPEAKER HI
(J3-2) VIOLET
NOTE 1
SPEAKER LO (J3-3) VIOLET
NOTE 1
PTT HI
(J3-5) WHITE
NOTE 2
MIC LO
(J3-4) BLACK
MIC HI
(J3-1) BROWN
PTT LO
(J3-6) WHITE
NOTE 2
J3
P3
J2
P2
NOTES:
1) CONNECT EITHER VIOLET WIRE TO THE RADIO
SPEAKER HI OUTPUT.
CONNECT THE REMAINING VIOLET WIRE TO
SPEAKER LO.
2) CONNECT EITHER WHITE WIRE TO THE RADIO
PUSH-TO-TALK (PTT) KEY LINE INPUT.
CONNECT THE REMAINING WHITE WIRE TO THE
PTT KEY LINE RETURN (PTT LO).
VOLUME
SQUELCH
R
UltraSound
INTERCOM
TIP
BARREL
RING
HEADSET JACK
CREW #2
(J1-9) TAN
