1987 MAZDA 626 Workshop Manual

15 INTRODUCTION
INTRODUCTION
HOW TO USE THIS SECTION
Information regarding removal and installation of electrical equipment is given in SECTION 14.
Understanding will be easier if this section is used in conjunction with the WIRING DIAGRAMS.
63U15X-002
ELECTRICAL TROUBLESHOOTING TOOLS
Test Light
The test light, as shown in the figure, uses a 12V bulb.
The two leads should be connected to probes. The
test light is used for simple voltage checks and to
check for short circuits.
Caution
When checking the control unit, never use a
bulb over 3.4W.
69G15X-002
Jumper Wire
The jumper wire is used for testing by short-circuiting
switch terminals and to verify the condition of ground
connections.
Caution
Do not connect the jumper wire between a
power source line and body ground, because
doing so may cause burning or other damage
to harnesses or electronic components, etc.
61G15X-002
Voltmeter
The DC voltmeter is used for measurement of circuit
voltage. A voltmeter with a range of 15V or more is
used. It is used by connecting the positive (+) probe
(red lead) to the point where voltage is to be meas-
ured and connecting the negative (-) probe (black
lead) to the body ground.
69G15X-003
15—2

INTRODUCTION 15
63U15X-005
BrY
YELLOW
BLACK BROWN
47U15X-008
Ohmmeter
The ohmmeter is used to measure the resistance be-
tween two points in a circuit, and is also used to check
for continuity and diagnosis of short circuits.
Caution
Do not attempt to connect the ohmmeter to
any circuit to which voltage is applied, be-
cause doing so may burn or otherwise dam-
age the ohmmeter.
PRECAUTION
Wiring Color Code
Two-color wires are indicated by a 2-letter symbol.
The first letter indicates the base color of the wire and
the second indicates the color of the stripe.

CODE COLOR

B
BLACK

Br
BROWN

G
GREEN

L
BLUE

Lb
LIGHT BLUE

Lg
LIGHT GREEN

0
ORANGE

R RED

Y
YELLOW

w WHITE
Bulkhead-Type Connector
This connector can be separated by pressing the lock
lever.
Do not pull the wire when removing the connector;
be careful to hold the connector itself when discon-
necting.
69G15X004
15-3

15 INTRODUCTION
69G15X-005
5BU15X-003
Inspection note
When checking the continuity or voltage with a cir-
cuit tester, insertion of the test probe into the recep-
tacle connector may open the fitting of the connector
and result in poor contact.
Therefore, insert the test probe only from the wire har-
ness side.
Replacement of Terminal
Use the appropriate tools to remove the terminal, as
shown in the figure.
When installing a terminal, be sure to press it in until
it locks securely.
< Female Type No.1 >
Insert a push-tool or thin piece of metal from the ter-
minal side of the connector, and then, with the lock-
ing tabs of the terminal pressed down, pull the
terminal out from the rear side.
< Female Type No.2>
5BU15X-004

Same as the female type.
47U15X-012
15—4

INTRODUCTION 15
69G15X-006
4BG15X-003
69G15X-007
/Wire
Shield braid wire
Insulation
Replacement of Fuse
1. When replacing a fuse, be sure to replace it with
one of the specified capacity.
If, after a fuse has been replaced, it fails again, there
is probably a short in the circuit, and the wiring
should be checked.
2. Be sure the negative battery terminal is disconnect-
ed before replacing a main fuse.
3. When replacing a fuse, use the supplied fuse puller
in the fuse box cover.
Thin Insulation Wire
To reduce the weight of the wiring harness, a thin
coating of high resistance insulation material is used.
Shielded braid wire
This wire is used to prevent a malfunction in impor-
tant circuits that are susceptible to outside signals or
interference.
Eg.
Ignition coil
02 sensor
69G15X-008
15—5

15 INTRODUCTION
ELECTRICAL SYMBOLS
Switches and Relays
There is an NC (normally closed) and NO (normally open) indication for switches and relays; this indi-
cates the condition when there has been no change of operating conditions.
Relay

NO type relay NC type relay
Switch
NO switch NC switch
Not
in
operation (No power supply)

—Jtfiifij —o o—

Flow Stop Flow
In operation (Power supply)
^
^aijuiy—'

Flow
l=3X

Stop
Flow
Stop

Other Electrical Symbols

Holder
Box —
© ©

Holder
Box —
Holder
Box —

BATTERY BODY GROUND FUSE FUSIBLE LINK

(£)
* 1 fc

MOTOR COIL, SOLENOID RESISTOR VARIABLE RESISTOR

1

ii
-L ©

THERMISTER DIODE CONDENSER LIGHT

1

TRANSISTOR SPEAKER CIGARETTE LIGHTER HEATER

69G15X-009
15—6

LOCATION OF UNIT, RELAY AND SWITCH 1 5
LOCATION OF
UNIT,
RELAY AND SWITCH
STRUCTURAL VIEW
Door SW
Power window SW
AAS control unit
Cruise control unit
Relay box
(EGI and Diesel model)
Engine control unit
Brake fluid level sensor
Main fuse block
(EGI model)
Main fuse block
(Carburetor model) | \ Relay box
Main fuse block Relay box
(Diesel model) (Carburetor model)
Power window SW
Door SW
Door lock SW
AAS control SW
CPU and joint box
86U15X-002
15-7

1 5 LOCATION OF UNIT, RELAY AND SWITCH
STRUCTURAL VIEW
Hatchback
Light and turn switch
Rear wiper switch
Rear washer switch
Front wiper and washer
switch, and cruise control switch
/ Hazard switch (Except RHD model)
Rear def. switch (Except ECE)
Rear fog light switch (For ECE)
AAS switch
Headlight cleaner switch
Remote control mirror switch
Heater control switch
Driving mode selector switch
Cruise control main switch
Coupe/MX-6 and Sedan

-nr
J

nu
iTPD'i
Rear def, switch (Except ECE) Hazarc
Rear fog light switch (For ECE)
switch (Except RHD model)
15-8
86U15X-003

MAIN FUSE BLOCK
1
5

MAIN FUSE BLOCK
STRUCTURAL VIEW
LHD
and RHD
General, Middle East,
ECE
(Carburetor model)
0

U
%
s
5
»

00000 USE
THE
DESIGNATED FUSE ONLY
ECE
(EGI
model)
£
o 2Z
o u
^ *5

4
-
<
—
o
O
n

2
O
<

a
HI

<
°
I®
a
o o-S
Ul 51 Ui
^

tB USE
THE
DESIGNATED FUSE ONLY
>1

P

West Germany (Carburetor
and EGI
model)
Q
o o
^
*S

lu

u
<
EL
°
33 JZ< gis
2 ? «
Q-
o
S3 ill
™

N
TiSE
THE
DESIGNATED
FU

Unleaded fuel model
(EGI)

USE
THE
DESIGNATED FUSE ONLY
PTC
30A
(Sweden)
HEAD
40A
(Sweden)
BTN
40A
(Sweden)
LHD
and RHD
General,
ECE
(Diesel model) Except Sweden
1 T
1
•N

HEATER
[
40A (COOLING FAN
[
30A

z
<
m
3
MAIN
BOA
;

/I
HEAD
40A
ADD
FAN 30A

/ xx
West Germany (Diesel model)

fl
,
v

K
<
t
o

,o
,

p <
f—
o
0.
o

86U15X-004
15—9