Subaru Legacy IV (2008 year). Manual - part 1188

WI-4

Basic Diagnostic Procedure

WIRING SYSTEM

3. HOW TO DETERMINE AN OPEN CIRCUIT

1) WITH VOLTMETER:
An open circuit is determined by measuring the
voltage between respective connectors and ground
using a voltmeter, starting with the connector clos-
est to the power supply. The power supply must be
turned ON so that current flows in the circuit. If volt-
age is not present between a particular connector
and ground, the circuit between that connector and
the previous connector is open.

2) WITH OHMMETER:
Disconnect all connectors affected, and check con-
tinuity in the wiring between adjacent connectors.
When the ohmmeter indicates “infinite”, the wiring
is open.

4. HOW TO DETERMINE A SHORT CIRCUIT

1) WITH TEST LIGHT:
Connect a test light (rated at approx. 3 watts) in
place of the blown fuse and allow current to flow
through the circuit. Disconnect one connector at a
time from the circuit. Starting with the one located
farthest from the power supply. If the test light goes
out when a connector is disconnected, the wiring
between that connector and the next connector
(farther from the power supply) is shorted.

2) WITH OHMMETER:
Disconnect all affected connectors, and check con-
tinuity between each connector and ground. When
the ohmmeter indicates continuity between a par-
ticular connector and a ground, that connector is
shorted.

Open circuit

WI-09860

Open circuit

WI-02743

Shorted wiring

Test light

Fuse holder

WI-02744

Shorted connector

WI-02745

WI-5

Basic Diagnostic Procedure

WIRING SYSTEM

C: HOW TO READ WIRING DIAGRAMS

1. WIRING DIAGRAM

The wiring diagram of each system is illustrated so
that you can understand the path through which the
electric current flows from the battery.
Sketches and codes are used in the diagrams.
They should read as follows:
• Each connector and its terminal position are indi-
cated by a sketch of the connector in a disconnect-
ed state which is viewed from the front.

• The number of poles or pins, presence of a lock are indicated in the sketch of each connector. In the
sketch, the highest pole number refers to the number of poles which the connector has. For example, the
sketch of the connector shown in figure indicates the connector has 9 poles.

WI-02746

Viewed from this direction

4

2

4

1

3

WI-02747

Connector used in  vehicle

Sketch

Symbol

Number of poles

Numbered in order from upper
right to lower left

Numbered in order from upper
left to lower right

Connector shown in wiring diagram

Double frames

Indicates a lock 
is included.

Indicates the number of poles.

4

3

2

1

9

8

7

6

5

Indicates a lock is included.

Single frame

1

2

3

4

5

6

7

8

9

WI-6

Basic Diagnostic Procedure

WIRING SYSTEM

• When one set of connectors is viewed from the
front side, the pole numbers of one connector are
symmetrical to those of the other. When these two
connectors are connected as a unit, the poles
which have the same number are joined.

• WIRING DIAGRAM:
The connectors are numbered along with the num-
ber of poles, external colors, and mating connec-
tions in the accompanying list.
• The sketch of each connector in the wiring dia-
gram usually shows the (A) side of the connector.
The relationship between the wire color, terminal
number and connector is described in the figure.

NOTE:
A wire which runs in one direction from a connector
terminal sometimes may have a different color from
that which runs in the other direction from that ter-
minal.

• In the wiring diagram, connectors which have no
terminal number refer to one-pole types. Sketches
of these connectors are omitted intentionally.

• The following color codes are used to indicate
the colors of the wires.

WI-00107

1

1

2

2

3

3

4

4

5

5

6

6

WI-02748

Wire color :

BR (No. 1 terminal)
RW (No. 3 terminal)

i2

3 4

1 2

BR

RW

i2

F4

1
3

(A)

B

B

B15

F10

WI-00109

Color code

Color

L

Blue

B

Black

Y

Yellow

G

Green

R

Red

W

White

Br

Brown

Lg

Light green

Gr

Gray

P

Pink

Or

Orange

Sb

Light blue

V

Violet

SA

Sealed (Inner)

SB

Sealed (Outer)

WI-00110

YL

2

YG

1

SB

10

YL

9

YG

8

SA

1

SB

22

SA

20

YG

YL

SB

SB

SA

WI-7

Basic Diagnostic Procedure

WIRING SYSTEM

• The wire color code, which consists of two letters
(or three letters including Br or Lg), indicates the
standard color (base color of the wire covering) by
its first letter and the stripe marking by its second
letter.

• The table lists the nominal sectional areas and
allowable currents of the wires.

CAUTION:
When replacing or repairing a wire, be sure to
use the same size and type of the wire which
was originally used.

NOTE:

• The allowable current in the table indicates the
tolerable amperage of each wire at an ambient
temperature of 40°C (104°F).
• The allowable current changes with ambient
temperature. Also, it changes if a bundle of more
than two wires is used.

• Each unit is either directly grounded to the body
or indirectly grounds through a harness ground ter-
minal. Different symbols are used in the wiring dia-
gram to identify the two grounding systems.

• The ground points shown in the wiring diagram
refer to the following:

NOTE:
All wiring harnesses are provided with a ground
point which should be securely connected.

Nominal 
sectional 
area

No. of 
strands/
strand 
diameter

Outside 
diameter of 
wiring

Allowable 
current
Amps/
40°C (104°F)

mm

2

mm

0.3

7/0.26

1.8

7

0.5

7/0.32

2.2 (or 2.0)

12

0.75

30/0.18

2.6 (or 2.4)

16

0.85

11/0.32

2.4 (or 2.2)

16

1.25

16/0.32

2.7 (or 2.5)

21

2

26/0.32

3.1 (or 2.9)

28

3

41/0.32

3.8 (or 3.6)

38

5

65/0.32

4.6 (or 4.4)

51

8

50/0.45

5.5

67

Y B

Black

Marking color :
Reference color :

Yellow

WI-03797

Direct ground

Indirect terminal
ground

B

WI-02750

WI-03791

: ABS GROUND

GA

: AIRBAG GROUND

GAB

: BODY GROUND

GB

: ENGINE GROUND

GE

: RADIO GROUND

GR

: VDC GROUND

GV

: REAR DEFOGGER GROUND

GD