light DATSUN PICK-UP 1977 Owner's Manual

CLEANING
AND

INSPECTION

Clean
all
disassembled

parts
but
do

not
use

grease
dissolving
solvents
for

cleaning

overrunning
clutch
annature

assembly

magnetic
switch

assembly

and
field
coils
since
such
a

solvent

would
dissolve

grease
packed
in

c1u
tch

mechanism

and
would

damage
coils
or

other
insulators

Check
them
for
excessive

damage

or

wear
and

replace
if

necessary

TERMINAL

Check
terminal
for

damage
and

wear
and

replace
magnetic
switch

assembly
if

necessary

FIELD
COIL

Check
field
coil
for
insulation
If

the
insulation
of
coil

is

damaged
or

worn
it
should
be

replaced

Testing
field

coil
for

continuity

Connect
the

probe
of
a

circuit

tester

or
an
ohmmeter
to
field
coil

positive
terminal

and

positive
brush

holder

If
tester
shows
no

continuity
field

circuit
or

coil
is

open

EE016

Fig
EE

I2
Testing
field
coil

for
continuity

TestIng
field
coD
for

ground

Place
one

probe
of
circuit
tester

onto

yoke
and
the
other

onto
field

coil
lead

positive
tenninal

If

very
little
resistance
is
read
field

coil
is

grounded
Engine
Electrical

System

EE017

Fig
EE

I3

Testing
rU
ld
coil

for

ground

BRUSHES
AND

BRUSH

LEAD

WIRE

Check
the
surface
condition
of

brush
contact

and
wear
of

brush
If
a

loose
contact
is
found
it
should
be

replaced

If
brush
is

worn
so
that

its

length
is

less
than
12
mm
0
472
in

replace

Check

the
connection

of
lead

clip

and
lead
wire

o

@

EE
8
Check
brush
holders
and

spring
cUp

to
see
if

they
are
not

deformed
or

bent
and
will

properly
hold
brushes

against
the

commutator

If

brushes
or
brush
holders
are

dirty
they
should
be

cleaned

BRUSH
SPRING

TENSION

Check
brush

spring
tension

by
a

spring
scale
as
shown
in

Figure
EE

13

The

reading
should

be
1

6

kg
3
5

Ib

Replace
spring
if

tension
is

lower
than

I
4

kg
3
1
Ib

ARMATURE

ASSEMBLY

Check
external

appearance
of

armature
and
commutator

1

Inspect
commutator
If
the
sur

face

of
commutator
is

rough
it

must

be
sanded

lightly
with
a
No

500

emery
cloth
If
the

depth
of

insulating

mica
is

less
than

0
2
mm
0

0079
in

from
commutator
surface

insulating

mica
should

also
be
undercut
so

that

its

depth
is
0
5
to
0
8

mm
0
01
97
to

0
0315
in

The
wear
limit
of
commutator
dia

meter
is

2
mm
0

0787
in
If
the

diameter
of
cammu

tator
is

less
than

31
mm
1
220
in

replace
annature

assembly

EE018

Fig
EE
14

Inspecting
brush

spring
tension

L

0
5
to
0
8
mm

71j

Correct

2

Inspect
soldered
connection
of

armature
lead

and
commutator
If

loose
connection
is
found
solder
it

using
resin

flux

3

Armature
test
for

ground

Using
a
circuit
tester

place
one

test

probe
onto
armature
shaft
and
other

onto
each
commutator
bar

If
tester

shows

continuity
armature

is

grounded
and
must
be

replaced

EE022

Fig
EE

16

Testing
annature
for

ground

4

Check
armature
for
short

by

placing
it
on
armature
tester

growler

with
a

piece
of
iron

over
armature

core

rotating
armature
If
the

plate

vibrates
armature

is
shorted

j
l

EE023

Fig
EE

17

Testing
annature

for

ahort
Engine
Electrical

System

L

File
l

0

Commutator

Segmen
t

IWMica

Incorrect

EE021

Fig
EE
15

Undercutting
i118ulating
mica

5
Check

armature
for

continuity
by

placing
probes
of

tester
on
two

seg

ments
side

by
side
If
tester
shows
no

continuity
the
circuit
is

open

OVERRUNNING
CLUTCH

ASSEMBLY

Inspect
pinion
assembly
and
screw

sleeve
Screw
sleeve

must
slide

freely

along
armature
shaft

splines
If

damage
is
found
or
resistance
is
felt

when

sliding
it
must
be

repaired

Inspect

pinion
teeth
If
excessive
rub

bing
is
found
on
teeth

replace

Flywheel

ring
gear
also
must
be
in

spected

l

EE278

Fig
EE
18

Overrunning
clutch

auem

bly

BRUSH

HOLDER
TEST

FOR

GROUND

Using
a
circuit
tester

place
one
test

probe
onto

negative
side

of
brush

holder

and
another
onto

positive
side

If

tester
shows

continuity
brush

holder
is

shorted
to

ground

Replace

brush

holder

EE
9
Ee026

Fig
EE
19

Testing
brush

for

round

BEARING
METAL

Inspect
bearing
metal
for
wear
or

side

play
If
the
clearance
between

bearing
metal
and
armature
shaft
is

more
than
0
2
mm
0
0079
in

replace

metal

MAGNETIC
SWITCH

ASSEMBLY

1

Using
a
circuit
tester

l
check

con

tinuity
between
S
terminal
of

mag

netic

switch
and
switch

body
metal
If

continuity
does
not
exist
shunt

coit
is

opened

Replace
switch

assembly

2
In
the

same
manner
as
above

check

continuity
between
terminals

S
and
M

If

continuity
does
not

exist
series

coil
is

opened

Replace
switch

assembly

ASSEMBLY

Reassemble

starting
motor
in

re

verse

sequence
of

disassembly

When

assembling
be

sure
to

apply

grease
to

gear
case
and

rear
cover

bearing
metal

and

apply
oil

lightly
to

pinion

TEST

PERFORMANCE
TEST

Starter
motor
should
be

subjected

to
a
no
load

test
whenever
it
has

been
overhauled
to
ensure
that

its

performance
will
be

satisfactory
when

installed
on

engine
Starter
motor

should
also
be

subjected
to

the
test

when
the
cause
of
abnormal

operation

is

to
be
determined

A
brief
outline
of

the
test
is

given
below

Condition
Engine
Electrical

System

Probable
cause

Starting
motor

cranks

slowly
Dirty
or
worn
commutator

Armature
rubs

field
coil

Damaged
solenoid
switch

Starting
motor

operates
but
does

not
crank

engine
Worn

pinion

Locked

pinion
guide

Worn

ring

gear

Starting
motor
will

not

disengage
even
if

ignition
switch
is

turned
off
Damaged
solenoid
switch

Damaged

gear
teeth

The

charging
circuit
consists

of
the

battery
alternator

regulator
and

necessary

wiring
to
connect
these

parts
The

purpose
of
this

system
is
to

convert
mechanical

energy
from
the

engine
into

electrical

energy
which

is

used
to

operate
all

electrically

operat

ed
units

and
to

keep
the

battery
fully

charged

When
the

ignition
switch
is

set
to

ON
current
flows
from
the

battery

to

ground
through
the

ignition
switch

voltage
regulator
IG
terminal

primary

side
contact

point
PI

movable

contact

point
P2

voltage

regulator

IF

terminal
alternator
IF
terminal

rotor

field
coil
and
alternator

E

terminal

as
shown
in

Figure
EE

23

by

full
line

arrow
marks
Then
the

rotor

in

the

alternator
is
excited

On
the

other
hand

current
flows

from
the

battery
to

ground

through
the

ignition

switch

warning

lamp
voltage
regula

tor
L

terminal

lamp
side
contact

point
P4

movable

contact

point

P5
and

voltage
regulator
E
termi

nal
as
shown

by
dotted

line
arrow
CHARGING
CIRCUIT

marks
Then

the

warning
lamp
lights

When
the
alternator

begins
to

op

erate
three

phase

alternating
current
is

induced
in

the

stator
armature
coil

This

alternating
current
is
rectified

by

the

positive
and

negative
silicon

diodes
The
rectified

direct
current

output
reaches
the
alternator
A

and

E

terminals

On
the
other
hand
the
neutral

point
voltage
reaches
N
and
E

terminals

nearly
a
half
of

the

output

voltage
and
current
flows
from

voltage
regulator
N
terminal
to
E

terminal
or

ground
through
the
coil

VCI
as
shown
in

Figure
EE
24

by

the
dotted
line
arrow
marks
Then
the

coil
VCI
is
excited
and
the

movable
contact

point
IPS
comes

into
contact
with

voltage
winding
side

contact

point
P6
This
action
causes

to
turn
off

the

warning
lamp
and

complete
the

voltage
winding
circuit

as
shown

by
the
full

line
arrow
marks

When
the
alternator

speed
is
in

creased
or
the

voltage
starts
to
rise

excessively
the
movable
contact

point

EE
12
Corrective
action

Clean
and

repair

Replace
assembly

Repair
or

replace

Replace

Repair

Replace

Repair
or

replace

Replace
damaged

gear

P2
is

separated
from

the

primary

side
contact
PI

by
the

magnetic

force

of
coil
VC2
Therefore

registor
RI
is

applied
into
the
rotor

circuit

and

output
voltage
is
decreased

AJ

the

output
voltage
is
decreased

the

movable
contact

point
P2
and

primary
side
contact
Pin

comes
into

contact
once

again
and

the
alternator

voltage
increases

Thus
the

rapid

vibration
of
the
movable

contact

point

IPl

maintains
an
alternator

output

voltage
constant

When
the
alternator

speed
is

further

increased
or
the

voltage
starts
to
rise

excessively
the

movable
contact

point

P2
comes

into
contact
with

secondllJ
side
contact

point
P3

Then
the
rotor
current
is

shut
off
and

alternator

output
voltage
is

decreased

immediately
This

action
causes

movable
contact
n
to

separate

from

secondary
contact
P3
Thus

the

rapid
vibration
of

the
movable

contact

point
P2

or

breaking
and

completing
the

rotor
circuit
maintains

an
alternator

output
voltage
constant

DESCRIPTION

REMOVAL

DISASSEMBLY

INSPECTION
AND
REPAIR

ROTOR
INSPECTION

INSPECTION
OF

STATOR

DESCRIPTION

In
the
alternator
a

magnetic
field
is

produced
by
the
rotor
which
consists

of
alternator
shaft
field
coil

pole

pieces
and

slip
rings
The

slip
rings

pressed
in
the
shaft
conduct

only
a

small
field
current

Output
current
is

generated
in
the
armature
coils
located

in

the
stator
The
stator
has
three

windings
and

generates
three

phase

alternating
current
Silicon
diodes
act

@God

A
tfff
Engine
Electrical

System

ALTERNATOR

CONTENTS

EE
15

EE
16

EE
16

EE
16

EE
17

EE
17
INSPECTION
OF
DIODE

INSPECTION
OF
BRUSH

SPRING
PRESSURE
TEST

ASSEMBL
Y

ALTERNATOR
TEST

SERVICE
DATA
AND
SPECIFICATIONS
EE
17

EE
1B

EE1B

EE

1B

EE19

EE
19

like
a
one

way
valve
for

electricity
so

that

charging
current

passes
easily
but

reverse
current
is
shut
out

In
this
alternator

pack
type
silicon

di
odes

are
used

Six

diodes
three

negative
and
three

positive
are
installed
in

positive
and

negative
plates
as
an

assembly

These
diodes
are
direct
soldered
at

their

tips
and
constructed
with

posi

3

2

I
4

e

o

e

9
tive
and

negative
conjunction

They
are
mounted
on
the
two

plates
which

combine
the
function
of

heat

dissipating
plate
and

positive

negative
terminals
and
are

light
in

weight
and

easy
to
service

The

pulley
mounted
on
the
air

conditioner
models
is

different
from

that
on
the

standard
models
without

air
conditioner

1

Pulley
usem

bly

2
Front
cover

3
Front

bearing

4

Rotor

5

Rear

bearing

6
Stator

7
Brush
assembly

8
Rear
cover

9

Diode
set

plate
assembly

10
Diode
cover

11

Through
botrs

EE
15
EE345

Fig
EE
26

Exploded
view

REMOVAL

1
Disconnect

negative
battery
ter

minaL

2

Disconnect
two
lead
wires

and

connector
from
alternator

3
loosen

adjusting
bolt

4

Remove
alternator
drive
belt

5
Remove

parts
associated
with

alternator
from

engine

6

Remove
alternator
from

vehicle

DISASSEMBLY

1
Remove

pulley
nut
and

pulley

assembly

11

C

@@@
EE033

Fig
EE
27

Removing
pulley
ond

fan

2
Remove
brush
holder

fIxing

screws
and
remove
brush
holder

cover
Pull
brush
holder
fOIWard

and

remove
brushes

together
with
brush

holder

Note
Do
not

disconnect
N
tenninaJ

from
stator

coil
lead
wire

EE346

1
N
terminal

2
Brush

holder

3
Brush
holder

co
r

Fig
EE
28

Remouing
brush
Engine
Electrical

System

3
Remove

through
bolts

Separate

front
cover
with

rotor
from
rear
cover

with
stator

by
lightly

tapping
front

bracket
with
a

wooden
mallet

J

J

4

C

EE035

Fig
EE
29

Separating
front
cover

with

rotor

from
rear

cover

4
Remove
three
set

screws
from

bearing
retainer

and

separate
rotor

from
front
cover

DO
Q
EE036

Fig
EE
3D

Removing
rotor

5

Pull

rear

bearing
out
from
rotor

assembly
with

a

press
or

bearing

puller

L

I
EE037

Fig
EE
3I

Pulling
out

of
roar

bearing

EE
16
6
Remove
diode

cover

fIXing
screw

and

remove
diode

cover
Disconnect

three
stator

coil
lead
wires
from

diode

terminal

with
a

soldering
iron

7
Remove

A
tenninaJ
nut
and
diode

installation

nut
and

remove

diode

assembly

CD

AJ

f
e

ecA

O

1
Diode

assembly

o

2
Diode
cover
o

EE039

Fig
EE
32

Removing
diode

088embly

Note
Use
care

in

assembly
to

on
it
handling
diode

an

undue

st

INSPECTION
AND

REPAIR

Remove

alternator
from
car

and

connect
a
circuit
tester
between
F

tenninal
and
E
terminal

When
the
resistance

is

approxi

mately
5il
the
condition
of

brush
and

fIeld
coil
is

satisfactory
When
no

continuity
exists
in
brush
or
fIeld

coil
or

when
resistance
differs

significantly
between
those

parts
dis

assemble
and

inspect

A

o
E

O

1

ld

Q

EE040

Fig
EE
33

Inspecting
alternator

Engine
Electrical

System

ALTERNATOR
TEST

Before

conducting
an

alternator

test
make
sure
th

tthe

battery
is

fully

charged
A

30
V
olt

voltmeter

and
suitable

test

probes
3re

necessary
for
the
test

Set

up
a
test
circuit

as
shown
in
Figure
EE45
and
test

auernator
in

the

manner
indica
ted
in

the
flow

chart

below

1
Disconnect

connectors
at
alternator

2
Connect
A

terminal
to
F

terminal

3
Connect

one

test
probe
from

voltmeter

positive
terminal
to

A
terminal

Connect
the
other
test

probe
to

ground

Make
sure
that
voltmeter

registers
battery
voltage

4

Turn
on

headlights
and

switch
to

High
Beam

5

Start

engine

6
Increase

engine
speed
gradually
until
it
is

approximately
1
100

rpm
and

take
the

voltmeter

reading

Measured
value
Below
12
5
Volts

Alternator
is
in

trouble
remove
and
check
it

for
condition
Measured
value
Over
12
5
Volts

Alternator
is
in

good
condition

Notes

a
Do
Dot
run

engine
at
the

speed
of

more
than
1
100

rpm
while
test
is

being
conducted
on
alternator

b
Do
not
race

engine

i
9
l

IV
I
Battery

EE052
Voltmeter

Fig
EE

45
Testing
alternator

SERVICE
DATA
AND
SPECIFICATIONS

Nominal

rating
V

A
LT138
IB

LTl35
36B
For
air

conditioner

1235

12
38

Negative
Negative

1
000
1

000

28
2
500

30
2
500

35
5

000
38
5
000

2
25

2
25

More
than

7
5
0
295
More
than
7
5
0
295

255

to
345
255

to
345

9
0
to

12
2

9
0
to

12
2

More
than
30
1
181
More
than

30
1
181

EE

19
Type

Ground

polarity

Minimum
revolution

when

generating

14V
with
no
load

rpm

Hot

output
current

Nrpm

Pulley
ratio

Brush

Length

Spring
pressure
mm
in

gr
oz

Slip
ring
outer
diameter
mm

in

ADJUSTMENT

VOLTAGE
REGULATOR

When
regulating
voltage
as
meas

ured
above
deviates

from
rated
value

adjust
regulator
in

accordance
with
the

following
instructions

I

Inspect
contact
surface
and
if

rough
lightly
polish
with
fine

emery

paper
1
500
or
600

2
Measure
each

gap
and

adjust
if

necessary
Adjust
core

gap
and

point

gap
in
that
order
No

adjustment
is

required
for

yoke

gap

3

Adjusting
core

gap

Loosen
screw
4
mm
0
157
in

diameter
which
is
used
to
secure

contact
set
on

yoke
and
move
contact

upward
or
downward

properly
See

Figure
EE
49

Core

gap

0
6

to
1
0
mm

0
024
to
0
039
in

EE398

I
Contact

set

2
ThicknesJ
gauge

3
4

mm
0
157
in
dia
screw

4

Crosshead
Jcrewdriver

Fig
EE
49

AdjUJJting
core
gap
Engine
Electrical

System

4

Adjusting

point
gap

Loosen
screw
3

mm
O
lIS
in

diameter
used
to
secure

upper
con

tact
and
move

upper
contact

upward

or
downward
as

necessary
See

Figure

EE
50

Point

gap

035

to
0
45
mm

0
014

to
O
D1S
in

EE399

I
Thicknes

gauge

2
3
mm

0
118
in
dia

screw

3
Cro
Sshelld

screwdriver

4

Upper
contact

Fig
EE
50
Adjusting

point
gap

5

Adjusting
voltage

Adjust
regulating
voltage
as

follows

Loosen
lock
nut

securing

adjusting

screw
Turn
this
screw
clockwise
to

increase
or
counterclockwise
to

decrease

regulating
voltage
See

Figure
EE
5

J
CD

EE400

I

Wrench

2

Crosshead
screwdriver

3

Adjusting
screw

4
l
ock

nut

Fig
EE
51

AdjUJJting
rel
Ulating
voltage

CHARGE
RELAY

Nonna

relay
operating
voltage
is
S

to
IOV
as
measured
at
alternator
A

tenninal

Relay
itself
however

oper

ates
at
4
to
5V

Use
a
DC
voltmeter
and
set

up
a

circuit

as
shown
in

Figure
EE
52

Adjust
charge

relay
in

the
same

manner
as
that
for

voltage
regulator

L

Connect

positive
tenninal
of
voltmeter
to

regulator
lead
connector
N
tenninal
with

negative
terminal

grounded

2
Start

engine
and

keep
it

idle

3
Take
voltmeter

reading

o
Volt

I
Check
for

continuity
be

tween
terminals
of
re

gulator
and
alternator

2
Alternator
circuit

inopera

tive
if

continuity
exists
Below
5
2
Volts

Charge
warning
lamp
on

I
Check
fan
belt
tension

2
If
correct
remove

regulator

and

adjust
as

necessary
Over
5

2
Volts

Charge
warning
lamp
on

Charge
relay
coil
or
contact

points
out
of
order

Replace
regulator

Over
5
2
Volts

Charge
warning
lamp
off

Charge
relay
assembly
is
in

good
condition

EE
23

CHECKING
AND

ADJUSTMENT

CAP
AND
ROTOR
HEAD

Cap
and
rotor
head
should
be
in

spected
periodically
as

specified
in
the

Maintenance
Schedule
Remove
cap

and
clean
all
dust
and
carbon
deposits

from

cap
and
rotor
If

cap
is
cracked

or
is

leaking
replace
with
a
De
one

CONTACT
POINT

Contact

point
should
be

replaced
in

accordance
with
the
Maintenance

Schedule

Standard

point
gap
is
0
45
to
0
55

mm
O
OIS
to
0

022
in
In

case
size

is
off
the
standard

adjustment
is
made

by
loosening
point
screws

Gap
gauge

is

required
for

adjustment

When

point
surface
is

rough
take

off

any
irregularities
with

fine
sand

paper
of
No
500
or
600
or
with
oil

stone

When
wear

on
contact

points
is

noticeable
replace
points
together

with
contact

arm
To

replace

proceed

as

follows

EE322

Fig
EE
58
Adju
ting
point

gap

EE321

I

Primary
lead
termina

2
Ground
lead
wire

3
Set
screw

4

Adjuster

5
Screw
Fig
EE
59
Breaker
Engine
Electrical

System

First
turn
out
set

screws
1
to

1
5

turns
at
contact
arm
and

primary
lead

wire

connection

just
for

enough
to

pull
out

primary
lead
terminal

Referring
to

Figure
EE

59
unSCrew

two
contact
set

fixing
screws

and

remove
lead
wire

While

holding
contact
arm

by

fingers

pull
out
contact
set

toward

you
by

raising
it

slightly
Contact

point
and

afm
can

then
be

removed

together

Install
new
contact

point
and

arm

assembly
in

reverse
sequence
of

removal

Coat
cam
with
a

light
coating

of

grease

ADVANCE
MECHANISMS

Specifications

Application

Vacuum
advance

Distributor

degrees
distributor

mmHg
inHg

Centrifugal
advance

Distributor

degrees

distribu
tor

rpm

For
Canada

Vacuum

advance
mechanism

mechanical

parts

If
vacuum
advance
mechanism
fails

to

operate
properly
check
for
the

following
items

and
correct
the
mal

function
as

required

1
Check
vacuum
inlet
for

signs
of

leakage
at
its

connection

Ifnecessacy

retighten
or

replace
with
a
new
one

2
Check
vacuum

diaphragm
for
air

leak

If
leak
is

found

replace
vacuum

controller

assembly

3

Inspect
breaker

plate
for
smooth

moving

If

pia
te
does
not

move

smoothly

this
condition
could
be
due
to

sticky

steel
balls
or

pivot
Apply
grease
to

steel
balls
or
if

necessary

replace

breaker

plate
as
an

assembly

EE
31
CONDENSER

Satisfactory
performance
of
con

denser

depends
on

capacity
and

degree

of
insulation

requiring
attention

to
be

sure

that
terminals
are
clean
and
set

screws
are

tight

Checking
of

condenser
is
made

by
a

condenser
tester

D4A4
06

D4A6
07
D4A4
07

D4A6
0S

Automatic

transmission
Manual
transmission

00
150
5

91

30
250
9

S4
00
170
6

69

6
50
300

1I
S1

00
550

11
0

2

300
00
600

110
1
950

Centrifugal
advance

mechanical

parts

When
cause
of

engine
malfunction

is

traced
to

centrifugal
advance
me

chanical

part
use
distributor
tester
to

check
its
characteristic

See
the

specifications
above

When

nothing
is

wrong
with
its

characteristic
conceivable
causes
are

break
down
abnormal

wearing
out
of

driving
part
or
others
So
do

not

disassemble

it

In

case
of

improper
characteristic

take
off
contact
breaker

assembly
and

check

closely
cam

assembly

governor

weight
shaft
and

governor
spring
etc

In
case

centrifugal
advance
me

chanical

part
is
reassembled
be

sure
to

check
advance
characteristic

by
dis

tributor
tester

Engine
Electrical

System

Transistor

ignition
unit

r
1
Power

switching

circuit
Duty

control

circuit

To
starter

To
distributor

Ba

ttery
Ignition
coil
1
Spark
timing

1
Signal
mom

toring
circuit
Lock

j
preven
ling

circuit

nm

Distributor

EE437

Fig
EE
75
Transistor

ignition
unit
circuit

diagram

REMOVAL
AND

INSTALLATION

Transistor

ignition
unit
is

located

on
the

right
hand
dash

side

panel
in

passenger
compartment

Disconnect

battery
negative
cable

2
Disconnect

wiring
harness
from

unit

3
Remove
two

setscrews
and
te

move
unit

4

To
install
reverse
the
order
of

removal

Note
Be

sure
to
connect

wiring
har

nesses
to
their

proper

positio

Failure
to
do
so
will

damage
the

unit

Refer
to

Figure
EE
76

Fig
EE
76
External
view

of

ignition

unit
INSPECTION

If
the

engine
does

not
run
due

to

faulty
ignition
system
check
the

igni

tion

system
as
follows

Check
for
a
cracked
distributor

rotor
or

cap
and
corroded
tenninals

Visually

inspect
high
tension
wires

for

condition
and
if

necessary
use
an

ignition
oscilloscope
or
a
circuit
tester

to
make

performance
checks
Check

spark
plugs
and

adjust
gaps
as
neces

sary

Replace
a

spark
plug
which

is
not

suitable
for
further
use
If
the

above

checks
cannot
correct
the

problem

check
the
entire

ignition
system
with

an

oscilloscope
or

a
circuit

tester

L
CHECKING
WITH
AN

OSCILLOSCOPE

An

oscilloscope
can
be
used
for

checking
almost

all
the
items
in

a

transistor

ignition
system

CHECKING
WITH
A

CIRCUIT

TESTER

A
circuit
tester
can
not
be

used
for

the

duty
control
circuit

and

power

t18nsistor

performance
tests

Both

methods
use
of

an

oscilloscope
and
a

circuit
tester

are
described
in
this

section

EE

37
The
items

are
classified

by
numerals

in

accordance
with
the

objective
of

checks
to

be

performed
Several

wiring

diagrams
are
found

on

pages
EE
41

to

EE
45
The
thick
lines
indicate

the

objective
of

each
individual
item

check

When

checking
a
circuit
with
an

oscilloscope
or
a
circuit
tester
be

careful
not
to

confuse
the

polarity
of

the
lead
wires
if

potential
difference

exists
between
the
check

points
at

which
the
lead
wires
are
to
be
con

tacted

Also
do
not

attempt
to
con

nect
the

lead
wires
to

any
points
in
the

circuit
other

than
those

designated

Careless

handling
of
the
lead
wires

will

result
in

damage
to
the
transistor

ignition
unit

as
well
as
to
the
oscillo

scope
or
circuit

tester

The
connection
of

a
tachometer

or

a

timing
light
in

parallel
with
an

oscilloscope
or
a
circuit
tester
is
al

lowable

provided
that
such
a

connec

tion
is

made
with
due
consideration
to

wiring
connections

1
POWER
SUPPLY

WIRING

AND

BAnERY
CHECK

See

wIrIng
diagram

In

FIgure
EE
88

Procedure

I
Turn
on

ignition
switch

2

Connect

a
circuit
tester
or

an

oscilloscope
as
shown
in
the

figure

below

DC
50
volt

range

EE302

Fig
EE
77

Checking
power
supply

wiring
and

batt

ry

Criterion

When

power
source

battery

voltage
is

indicated
OK

Lower

or
no
indication
N
G

If
the
result

is
N
C
Take

the

following
measures

I
Check
BW
and
B
color

wire

harness

respectively
for

proper
con

ductance

2

Check

battery
terminals

for

proper
connection

3
Check

charge
condition
of
bat

tery
if
an

excessively
low

voltage
is

indicated

2

CONTINUITY
CHECK
OF

PRIMARY
CIRCUIT

2
1

CheckIng
prImary

circuit
See

wiring

diagram

In

Fig
EE
89

Proced
ure

I

Disconnect

L
color
wire

from

ignition
unit

2

Turn
on

ignition
switch

3

C
ooneet
a
cireui
t

tester
or
an

oscilloscope
as
shown
in

Figure
EE
78

DC

50
volt

range

tf
S

EE303

Fig
EE

78
Checking
primary
circuit

Criterion

When

Donnal

power
Source

battery

voltage
is

indicated

OK

Lower

or
no
indication

N

G

If
the

result
is

N
C

Take

the

following
measures

1

Check
BW

and
L
color

wire
Engine
Electrical

System

harness

respectively
for

proper
con

ductance

2

Check
resistor

and

ignition
coil

terminals
for
loose

contact

3

Check
resistor
and

ignition
coil

for

discontinuity

4
Check

WB

color
wire
harness

of

ignition
coil

assembly
for

proper

continuity

2
2

Chacklng
IgnitIon
coil

auembly
See

wiring

diagram
In

Fig
EE
90

Procedure

I

Disconnect

ignition
coil
and
dis

tributor

harness
from

ignition
coil

external
resistor

2

Connect
a
circuit
tester
as

shown

in

the

figure
below

Resistance

1

range

Q

o
fD

ro

EE336

Fig
EE
79

Checking
ignition
coil

assembly

Criterion

When

approximately
1
6

to

2

0

ohm
is

indicated

OK

More

than
2

0
ohm

N
C

If
the

result
is

N
C

Replace

ignition
coil

assembly

3
PICK

UP

COIL

CONTINUITY

CHECK

See

wirIng
dIagram
In

Figure
EE
91

Procedure

Disconnect
R

and
G

color

wires
from

ignition
unit

2
Connect

a
circuit

tester
as
shown

in
the

figure
below

EE

3B
Resistance

10

range

fp

EE305

Fig
EE

BO

Checking
pick
up
coil

Criterion

When

approximately
720
ohm

is

indicated

OK

Far
less
than
or
more

than

720
ohm
N
C

If

the
result
is
N
C

Replace

pick

up
coil

assembly

4

PICK
UP
COIL
POWER

SIGNAL

PULSE
CHECK

Procedure

I

Disconnect
anti

dieseling
solenoid

valve

connector

2

Connect
a
circuit

tester
as

shown

in

the

figure
below

3

Rotate
starter

motor

4

Read
the
tester
indication

AC
2
S
volt

range

EE306

Fig
EE
81

Checking
pick
up
coil

power

aignal
pulse

Criterion

When

pointer
deflects

slightly
OK

When

pointer
does
not
deflect

at
all

N
C

If
the

result
is

N
C

Replace

pick

up
coil

assembly