1977 DATSUN PICK-UP battery

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

Engine
Electrical

System

r
l

I

I

I

i

r
Ye
Ff
p

Stator
ma

ture
coiJ

FF
vw

I

I
RI

L

Rot
r

field
C
oil

e
R

I

I

I
I

I

J

1
J

Alternator

Voltage
regulator
11

t

c

I

Fusible
link

t
8

c

J
5

9

i
c
c

0

Battery

t
u
J

EE029

Fig
EE
23

Charging
circuit

II

p
ns

1

Slator
ar

ature
coil

teJ

U

2iI
I

r
R
l
I

I

A3

R2
0
Fusible
link

Roto
field
coil

e

I
I
t
I

I
PS

M
g

j

t

i

H
U

Battery

Lh

A

l
a
o
J

L

V

It

g
t

f

EE030

Fig
EE

24

Charging
circuit
II

EE

13

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

MEASUREMENT

OF
REGULATOR

VOLTAGE

Regulator
voltage
is
measured
with

regulator
assembled
with
alternator

When

measuring
voltage
with

regulator

mounted
on

car
it
is

necessary
to

rotate

engine
at

high
speed

Connect
DC
voltmeter

l5
30Y

DC

ammeter

l5
30A

battery
and
a

O

25fl

resistor
rated

at
25W
with

cables

as
shown

I

Check
to
be
sure
that
all
electrical

loads
such
as

lamps
air

conditioner

radio
etc
are
turned
off

2

Before

starting
engine
be
sure
to

make
short
circuit
with
a

cable
be

tween
fuse
side
terminal
of
resistor

O
25fl

and

negative
side
terminal
of

ammeter
Failure
to
follow

this

pre

caution

will

cause
needle
of
ammeter

to

swing

violently
resulting
in
a
dam

aged
ammeter
Engine
Electrical

System

Genera

tor

A

r

iJ

IG

Fuse
box

i
B
Rqulator

Connector

Wire
harness

Short
circuit
here
between

fuse
side

tenninal
and

terminal
of
ammeter

before

starting
the
operation

Ammeter

lOA
V

Voltmeter
30V

EE055

Fig
EE
48

Measuring
regulator
voltage
with

regulator
on
vehicle

3
Refer
to
the

following
chart
to

determine
if

regulator
and
relative

EE
21
parts
are
in

good
condition

Engine
Electrical

System

I

Start

engine

2
Rotate

engine
at
2
500

rpm
for
several

minutes

Mter

racing
for

several
minutes

ammeter

reading

below
SA
After

racing
for

several
minutes

ammeter

reading
over
5

A

Fully

charged
battery
available

I

Replace
with

fully
charged

battery

2
Check

to
see
if
current
falls

below
SA
Fully
charged

battery
not
available

I
Connect
a

0
25
ohm

resistor
in
series

Current
falls
below

SA

Current
does

not
fall
below

SA

Recharge
battery
and

see
if

current
falls

below

SA

Reduce

engine
speed
to

idling
and
then

raise
it

to
2
500

rpm
while

observing
needle
of
voltmeter

Needle
of

voltmeter
held
within
limits

shown
in

the
below

table

Regulator

functioning
properly
Needle
of
voltme
ter
ou
t
of
limits
shown
in

the

following
chart

Adjust
or

replace
regulator

Regulator
type
TLI

Z
85C

Temperature
Oc
OF

Voltage
V
speed

c

Voltage

may
be

approximately

0
3
V

higher
than
rated
for
two
to

three
minutes
after

engine
is

start

ed
or
more

specifically
when

regu

lator
becomes
self
heated

Measure

ments
should

then
be
made

within

one
minute

after

starting
engine
or

when

regulator
is

cold

d
The

regulator
is

of
a

temperature

compensating
type
Before
meas

uring
voltage
be

sure
to
measure

surrounding
temperature
and
cor

rect

measurements

according
to
the

table
at
left
10

14

0

32

10

50

20
68

30
86

40
104
14
75
to
15

75

14
60
to
15
60

14
45
to
1545

14

30
to

15
30

14

15
to
15
15

14

00
to

15
00

Notes

3
Do

not
measure

voltage
immediate

ly
after

driving
Do
this
while
regulator
is
cold

b

To
measure

voltage
raise

engine

speed
gradually
from

idling
to

rated

EE
22

Engine
Electrical

System

RegulatoI

r
Yellow
terminal

A
W
L
WR

IG
WL

N

Y
E
B
F
WB
Voltmeter

Fig
EE

52
Tuting

charging
re
Qy
EE348

SERVICE
DATA
AND
SPECIFICATIONS

Voltage
legulator

Type

Regulating
voltage
with

fully

charged
battery

Voltage
coil

resistance

RotOI
coil

inserting
resistance

Voltage
coil

series
resistance

Smoothing
resistance

COle

gap

Point

gap

Ch
uge
lay

Release

voltage

Voltage
coil

resistance

Core

gap

Point

gap
v

fl

nun
in

nun
in

V

fl

nun
in

mID
in
TLl

Z
S5C

14
3
to
15
3
at

200C
680F

10
5
at
200C
680F

10

31

40

0
6
to
1
0
0
024
to
0
039

0
35
to
0
45

0
014
to
O

OIS

4
2
to
5

2
at
N
terminal

37
S
at
200C
680F

0
8

to
1
0
0
031
to
0
039

0
4
to
0
6
0
016
to
0
024

Standard

tempelatUIe
gIlIdient
O
OISV
oC

EE
24

NON
CALIFORNIA
MODELS
Engine
Electrical

System

IGNITION
CIRCUIT

CONTENTS

EE
26

CALIFORNIA
MODELS
EE
2B

NON

CALIFORNIA
MODELS

The

ignition
circuit
consists

of
the

ignition
switch
coil

distributor

wiring
spark
plugs
and

battery

The
circuit

is

equipped
with
a

resistor

During
cranking
electrical

current

bypasses
the
resistor

thereby

connecting
the

ignition
coil

directly
to

battery
This

provides
full

battery

voltage
available
at
coil
and

keeps

ignition

voltage
as

high
as

possible

The

low

voltage
current
is

supplied

by
the

battery
or

alternator
and

flows

through
the

primary
circuit

It
consists

of
the

ignition
switch
resistor

primary
winding
of
the

ignition
coil

distributor
contact

points
condenser

and
all

connecting
low
tension

wiring

The

high

voltage
current
is

pro

duced

by
the

ignition
coil

and
flows

through
the

secondary
circuit
result

ing
in

high

voltage
spark
between
the

electrodes
of

the

spark
plugs
in

engine

cylinders
This
circuit
contains

the

0
cl

Battery

Ignition
coil
secondary
winding
of

the

ignition
coil

high
tension

wiring
distributor
rotor

and

cap

When
the

ignition
switch
is

turned

on
and
the

distributor
contact

points

are
closed

the

primary
current

flows

through
the

primary
winding
of
the

coil
and

through
the

contact

points
to

ground

When
the

contact

points
are

opened

by
the

revolving
distributor
earn
the

magnetic
field
built

up
in
the

primary

winding
of
the

coil
moves

through
the

secondary
winding
of
the

coil

inducing

high
voltage
The

high

voltage
is

produced

every
time

the

contact

points

open
The

high
voltage
current

flows

through
the

high
tension
wire

to
the
distributor

cap
Then
the
rotor

distributes
the
current
to

one
of
the

spark

plug
terminals
in
the
distributor

Re5istor

To

starter

Secondary

winding

Cap

Breaker

point

f

Distributor

EE
26
cap

Then
the

spark
obtains
while
the

high
voltage
current

jumps
the

gap

between
the

insulated
electrode
and

the

ground
side
electrode
of
the

spark

plug
This

process
is

repeated
for
each

power
stroke
of

the

engine

The
distributor
contact

point
and

spark
plugs
should
be

inspected
clean

ed

and

regapped
at

tune

up
They

should
also
be

replaced
periodically
as

specified
in

the
Maintenance

Sched

ule
In

addition

apply
grease
NLGl

consistency
No
I

containing

MoS2
or

equivalent
to
distributor

shaft
and

grease
MIL
G
l0924B

containing

MoS2
or

equivalent
to
cam
as
reo

quired

The
remainder

of
the

ignition

component

parts
should
be

inspected

for

only
their

operation
tightness
of

electrical
terminals
and

wiring
con

dition

The

ignition
circuit
is
shown
below

IR

IB

I

is
21

J
g

Rotor

head

EE060

Fig
EE

53

Ignition
ydem
circuit

diagram