Volvo Truck Corporation
Service Bulletin
Göteborg, Sweden Trucks
Date Group No. Release Page
Discard previous Service Bulletin 370–125–01 from 7.16 370 125 03 1(17)
1.02.
Wiring diagram user manual
VERSION4
Wiring diagram user manual
T3114941
Contents
“General information on the wiring diagram”, page 2
“How to read the sub-diagram”, page 4
“How to find the correct sub-diagram”, page 10
“Cable harnesses”, page 14
“Abbreviations”, page 17
89260853
ENG77696 English
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 2(17)
General information on the wiring diagram
In the wiring diagram the entire diagram is divided into a What the cable harnesses are called and on which page
number of sub-diagrams. Each sub-diagram contains one they can be found is given in the cable harness list.
or more functions. Which functions are included and on At the end of wiring diagram are also lists of all the com-
which page the sub-diagram can be found can be seen in ponents, fuses, ground connections and connectors in the
the sub-diagram list. vehicle.
The two letters to the left of the text can be found again
above each sub-diagram on the right-hand side. The letter
combination is used for referring between different sub-
diagrams.
In the wiring diagram there are also illustrations showing
how most of the cable harnesses are laid in the vehicle.
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Wiring diagram structure
In order to minimise the number of sub-diagrams, draw-
ings of the maximum variants are found on each sub-dia-
gram. Therefore remember that all components and
cables are not always given for each respective chassis.
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Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 3(17)
New component number standard
A new component number standard complying with “DIN It comprises one letter, two numbers and occasionally a
40719 Part 2” has been introduced. suffix for a variant or position.
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Example
A Control units, fuse holder, refrigerator
B Sensor, loudspeaker, camera
C Capacitors
D Time control
E Lamps, heater
F Fuses
G Battery, alternator
H Horn, reversing warning unit
K Relays
L Reactors
M Motors
N Regulators
P Display
Q Circuit breaker
R Parking heater, cigarette lighter, resistors
S Switches, contacts
T Transformers
U Modulators, voltage converter
V Diodes
W Antennae
X Connectors
Y Solenoid valves, electric fuel pump, air-bag
Z Electric filters
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 4(17)
How to read the sub-diagram
The following pages show examples of the commonest
symbols used in the wiring diagram and also examples in
sub-diagrams with explanatory text.
Examples of symbols in the wiring diagram
Battery
Connector
Fuse
Junction point
Cable
Conductor on circuit board
Twisted cables
Twisted screened cables
Several cables screened
Coaxial, single, screened
Coaxial, double, screened
Earth connection with cable
Earth connection without cable
Switch
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 5(17)
Switch, starter switch
End switch
End switch, pressure controlled
Switch, temperature controlled
End switch, timer controlled
Relay
Bulb
Headlamp module
Rear lamp module
Alternator
Starter motor
Washer motor
Solenoid valve with diode
Electric magnetic coupling
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 6(17)
Pressure sensor
Temperature sensor
Level sensor
Starting element
Cigarette lighter
Horn
Rheostat
Buzzer
Speaker
Terminal block
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 7(17)
Sub-diagram example
Sub-diagram title, variant and symbol.
Coordinates (B 1).
Junction point.
Fuse.
Reference to diagram BA, Coordinates 0 C, Component
A17, Connector PA pin 29.
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 8(17)
The maximum variant is drawn, remember that all cables
and components are not always found on each respective
chassis.
Switch.
Relay.
Conduction path on circuit board.
Connector MB pin 9.
Conduction area and colour.
Thin lines, cables.
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 9(17)
Earth connection point 4, earth connection 1 and pin 2.
Earth connection to circuit board.
Earth connection without cable.
The same junction point can be drawn on several dia-
grams. The wire from the junction point to the earth point is
drawn but is only designated on one diagram. On the other
diagrams the earth point is written next to the junction
point. Suffix (A) indicates which junction point it is in the
chain from the earth point.
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 10(17)
How to find the correct sub-diagram
The following example shows four different ways of find-
ing the correct sub-diagram. The first method is the com-
monest and is the one most frequently used. Methods
two, three and four are not used as often but it is good to
know what they are.
1 Sub-diagram
If you want to find the right place in the motor sub-diagram
you look in the sub-diagram list.
The list tells you where you can find the motor sub-dia-
gram in the wiring diagram.
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Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 11(17)
2 Sub-diagram component number
If you know what the component number is of a compo-
nent included in the sub-diagram you can look in the com-
ponent list in the wiring diagram.
For example, you can look through the cable harness il-
lustrations and find the component number there.
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Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 12(17)
3 Sub-diagram connector
If you want to find out which component is connected to
connector MA, pin 7, you look in the list of connectors.
There you see which sub-diagram connector MA, pin 7,
appears in.
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Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 13(17)
4 Sub-diagram fuse
If you want to look up fuse F42 you can do this by looking
through the list of fuses to see the sub-diagram in which
the fuse is included.
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Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 14(17)
Cable harnesses
At the end of the wiring diagram is a principle drawing
showing all the cable harnesses and how they are con-
nected to each other with different connectors.
Before the principle drawing is a list of all the wiring har-
nesses. The list gives the cable harness names and if
there are illustrations of the cable harnesses, the page
numbers of the illustrations are given.
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Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 15(17)
How to find the correct cable harness
There are two ways of finding the correct wiring harness
for a component.
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The wiring harness number is written by the component
The simplest way is to look up the correct component number will come after the component. Remember that
number in the list of components. If the component is not all variants are always illustrated.
drawn on any of the illustrations, the cable harness
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 16(17)
The second method is if you, for example, want to find out The name of the cable harness and the page number of
on which cable harness component Y25 (solenoid valve the illustrations of the cable harness is given in the list of
block, levelling control, air suspension) is, you can look it cable harnesses, see 3.
up on the sub-diagram containing the component. In the The component or the component connector with the
sub-diagram you look up the connector to which the com- component number is drawn on one of the illustrations.
ponent is connected, in this case connector “BN”, see 1.
Look up connector “BN” in the principle illustration of ca-
ble harnesses at the end of the wiring diagram. In the il-
lustration you see that the connector is connected to
cable harness 1072 “cable harness air suspension chas-
sis”, see 2.
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How to find the cable harness for a component
Volvo Truck Corporation Date Group No. Release Page
Service Bulletin 7.16 370 125 03 17(17)
Abbreviations
At the end of the wiring diagram are two lists explaining
the meanings of the different abbreviations that appear in
the wiring diagram.
The first list explains the abbreviations in all sub-diagrams
and in the cable harness illustrations. The second list ex-
plains the different cable colours.
