ECU DATSUN PICK-UP 1977 Service Manual

INSPECTION

Evaporator

Check

evaporator
for

leakage
or

damage
If

damaged
replace

Expansion
valve

Check

expansion
valve
for

leakage

or

clogging
If

clogged
clean
filter
in

expansion
valve
If

damaged

replace

RECEIVER
DRYER

AND

PIPING

REMOVAL
AND

INSTAUATION

Receiver
dryer

I
Disconnect

battery
ground
cable

2

Discharge
system
Refer
to

Dis

charging
System
under
General
Service

section

3

Disconnect

compressor
lead
wire

at

connector

4

Disconnect

cooling
pipes
at

joints

Acno

Fig
AC
39

Diaconnecting
coo

ing

pipes

Notes

a

Plug
all

piping

joints
immediately

after

pipe
disconnection
to

prevent

entry
of
dust
or
moisture
laden
air

into

receiver

dryer
or
air
aJOdi

tioning
system

b
Use

two
wrenches
when
dIsconnect

ing
cooling
pipes

5

Remove
four
screws

securing

receiver

dryer
bracket

to
vehicle

body

and
detach

compressor
relay
and

pres

sure
switch
as
an

assembly

6
To

install
receiver

dryer
and

piping
reverse
the
order
of
removal
Air

Conditioning

Notes

a

Apply
a
coat
of
fresh

compressor

oil
to

sealing
surfaces
when
con

necting
cooling

pipes

b
Use
two
wrenches
when

connecting

cooling
pipes

c

Evacuate

cooling
system
then
re

charge
with

refrigerant

Refer
to

Evacuating
and

Checking

System
under
General
Service

sec

tion

d
Check

refrigerant

leakage
if
neces

sary
repair

Refer
to

Evacuating
and

Charging

System
under

General
Service
See

tion

Condenser

Disconnect

battery

ground
cable

2

Discharge

system
Refer

to
Dis

charging
System
under
General

Service

section

3
Drain

engine
coolant

4

Remove
radiator

grille

5

Remove

radiator

shroud
and

radiator

On
automatic
transmission

models

disconnect
both

torque
converter
oil

hoses

Note

While

cooling
water
is
hot

take

precautions

against
scalding

6
Disconnect
two

pipes
from

con

denser
remove
two

screws

securing

condenser

Condenser

can
now
be

removed

AC485

Fig
AC

40

Removing
conden
er

Notes

a
Use

two
wrenches
when
disconnect

ing
pipe

joints

b

Plug
openings
immediately
after

disconnecting
pipes

7

To
install

reverse
the
order
of

removal

AC

29
Tightening
torque

Flare
nut
for

copper
tube

from

compressor

2
5
to
4
0

kg
m

i8
to
29
ft
Ib

Flare
nut

for

copper
tube

to
receiver

dryer

2
5

to
3
5

kg
m

i8
to
25
ft
lb

Notes

a
When

disconnecting
and

connecting

cooler

pipes
be
sure
to

use
two

wrenches

b

Apply
a
coat
of
fresh

compressor

oil
to

sealing
surfaces
when

con

necting
cooler

pipes

c

To

prevent

possibility
of

explosion

due
to

high

pressure
within

cooling

system
do

not
clean
condenser

with
steam

Always
use
cold
water

or

cold

compressed
air

d
Evacuate

cooling
system
then
re

charge
with

refrigerant

Refer
to

Evacuating
and

Charging

System
under
General

Service
sec

tion

e
Check

refrigerant
leakage
if
neces

sary
repair
Refer
to

Checking
for

Leaks
under
General
Service

sec

tion

INSPECTION

RecelYer

dryer

Check
for

refrigerant
leakage
or

damage

Check
for

proper
connection
of

two

lead
wires

running
to

pressure

switch

If

any
component

part
is
found

damaged
replace
receiver

dryer
and

pressure
switch
as

an

assembly

Condenser

I

Check

inlet
and
outlet

pipe
joints

and

sealing
surfaces
for

damage
Re

place
parts
if

damaged
or

leaky

2

Clogged
condenser
fins
or

air

pas

sages
may
reduce

cooling
efficiency
of

condenser
Clean
these

areas
with

dry

compressed
air

Piping

Check

piping
for

leakage
If

leakage

occurs
at
connections

retighten

connecting
nuts

Replace
if

leakage

persists

MAINTENANCE

Replace
any
wiring
harness
which
is

cracked
deteriorated
or

poorly
in

sulated

Always
replace
wire
with
those
of

the

same
diameter
Do

not
use
wire
of

smaller
diameter

Where

necessary
securely
retain

wire
harnesses
with

clips
or

tapes
so

that

they
will
not
be

frayed
or
worn

by
vibration

Notes

a

Repair
or

replace
any
electrical

part

which
is

questionable
or
likely
to

cause
a
short
circuit

When
disconnecting
battery
cables

always
disconnect

ground
cable
be

fore

positive
cable
Clean
battery

and
terminals
before

connecting

cables
then
connect

positive
cable

and

ground
cable
in

that
order

Apply
a
coat
of

grease
to
terminals

to

prevent
rust
formation

b
Do
not

attempt
to
conduct
a
con

tinuity
test
with
a

screwdriver
or

service
tools

always
use
test
lead

wires

c
Do
not

ground
terminals
when

circuits
are

open
or
unloaded

always
use

a
test

lamp
12V
3W

or
circuit
tester
as
a

load

MAIN
RELAY

Removal
and
Installation

The
main

relay
is
attached
to
the

cooling
unit

I

Disconnect

battery

ground
cable

2

Disconnect
main

relay
lead
wires

at
connector

3

Remove

cooling
unit

assembly

Refer
to
Removal
and
Installation

under

Cooling
Unit

4
Remove
the
screw

securing
main

relay
to

cooling
unit

and
detach
main

relay

5

To
install
main

relay
reverse
the

order

of
removal

Inspection

To

check

continuity
in

relay

circuit
use
a

test

lamp
or
an
ohm

meter

Continuity
between

points
3

and
4
should
exist
Air

Conditioning

When
a
12

volt
d
c
is

applied
across

points
3
and
4

continuity
between

points
I
and
2

should
also
exist

CD

00

COMPRESSOR
RELAY

Removal
and
installation

Disconnect

compressor
relay
lead

wires

at
connector

2
Remove

two
screws
securing
com

pressor
relay
to
receiver

dryer
and

detach

compressor
relay

3
To
install

compressor
relay
reo

verse
the
order
of
removal
@

I
ul

CDe
JOO

ID
IDe

@e

L

AC465

Fig
AC
42
Main

relay

Inspection

Using
a
test

lamp
or

an
ohmmeter

make

sure
that

compressor
relay
con

tacts

open
and

close
con

tinuously

Continuity
always
exists
between

points
3
and
4
When

current
flows

through

points
3

and
4

points
1

and
2
close
This

causes
current
to

flow

through
1
and
2

FAN
SWITCH

Removal
and
installation

1
Disconnect

battery
ground
cable

2
Remove

screws

securing
console

box
Withdraw
console
box
forward

and
disconnect
lead
wire
connector

3
Detach
switch
knob

4
From
rear
side
of
console
box

remove
screws

securing
switch
and

remove
switch

5
To
install
fan
switch
reverse
the

order
of
removal

AC
31
i
t
v

J

AC489

Fig
A

C
43
Compressor
relay

AC771

Fif
AC

44
Removing
fan
switch

Inspection

Check

continuiry
in
fan
switch

circuit
with
a
test
lamp
or

an
ohm

meter

I

011
I
2
3

ICD

Tt

tt

AC772

Fig
AC
45
Fan
switch

RESISTOR
FOR
FAN
SWITCH

Removal
and
Installation

I

Disconnect
battery

ground
cable

2
Remove

glove
box

3
Remove

cooling
unit
Refer
to

Removal
and
Installation
under

Cooling
Unit

4

Disconnect
resistor
lead
wires
at

connector

@

O
sn
I
3n

CD
00
@

AC492

Fig
AC

46
Resistor

for
fan
switch
Air

Conditioning

5

Remove
resistor

assembly
from

upper
side
of

cooling
unit

Resistor
is

inserted
into

case

6
To
install

res
istor
for
fan
switch

reverse
the

order
of
removaL

Inspection

Test

continuity
between
resistor

and
fuse

THERMO
SWITCH

Removal
and
installation

1
Disconnect

battery

ground
cable

2

Remove

glove
box

3
Remove

duct
from

cooling
unit

4

Disconnect
thermo
switch
control

cable
and
lead
wires

5

Remove
thermo
switch

Note

Capillary
lube
is
fitted
into

groove
in
cooler
unit

6
To

install
thermo
switch
reverse

the

order
of
removal

I

I

AC773

Fig
AC
47

Removing
thermo
switch

AC

32
Inspection

I

Fully
move
thermo
swirch
lever

to
COLD

2

Test

continuity
between

ter

minals
with
a
test

tamp
or

an
ohm

meter

Continuity
should
exist

3

Dip
capillary
tube
end

into
ice

water
Test
continuity
between
ter

minals

Continuity
should
not
exist

4

Replace
if
switch
is

found
dam

aged

F
I
C
D
SOLENOID
VALVE

Removal
and
installation

I

Disconnect
battery
ground
cable

2
Disconnect
lead
wires
and
vacu

um

tube

3

Remove
two
screws
securing
sole

noid

valve
and
remove
solenoid
valve

AC77
4

Fig
AC

48
Removing
F
l
C
D

solenoid
valve

4
To
install
solenoid
valve
reverse

the
order
of
removal

Inspection

1
Test

continuity
in
solenoid
valve

circuit
with

a
test

lamp
or
an
ohm

meter

2
Turn
both
fan
switch
and
thermo

switch
on

3
Run

engine
at
idle
and
check
to

be
sure
that
vacuum
is

present
in
line

between
solenoid
valve
and

diaphragm

Air

Conditioning

1foo

1t
1

t7
LV

I
1
Clutch
wheel

bearing

2

Snap
ring

3

Clutch
wheel

assembly

4

Magnet
coil

5

Shaft
seal

assembly

6

Service
valve

7

Flange
valve

O

ring

8

Cylinder
head

9

Cylinder
head

gasket

10

Cylinder
gasket

11
Valve

plate
assembly

12
Base

plate
gasket

13
Base

plate

14
O

ring

15
Oil
filler

plug

16
Clutch

assembly

17

Compressor
assembly

COMPRESSOR

CLUTCH

The
most

likely
source
of

problem

is
clutch

slippage
Factors
are
listed

here

Exercise

ample
care

I

Clearance
between
clutch

hub

and

pulley
should
be
0
4

to
0
6
mm

0
016
to

0
024
in

at
all

peripheral

points

2
Make
sure
that
there
is

no
oil
or

dirt

on
friction
surfaces
of
clutch

disc

clutch
hub
and

pulley
Remove

oil
or

dirt

with
clean
lint
free
cloth

3
Make
sure
that
terminal

voltage
at

magnetic
coil
is
above
IO
5V

REMOVAL

I

Using
Clutch

Spanner
Wrench

hold
clutch
hub
With
suitable

socket

wrench
remove
bolt

retaining
clutch

hub
to
crankshaft
H

@
@

AC776

Fig
AC
51

Remouing
bolt

2
Then

using
Clutch

Removing

Bolt
remove
clutch

assembly
from

cmnkshaft

Fig
AC
52

Removing
clutch

AC34
AC775

Fig
A
C
50

Exploded
view

of

compressor

3

Loosen
four

electromagnetic
coil

mounting
screws
Coil

assembly
can

then
be

taken
out

easily

Fig
A
C
53

Removing
magnetic
clutch

INSTALLATION

Locate
the

electromagnetic
coil

at

the

correct

position
on

compressor

housing
Then
secure
four

electro

magnetic
coil

mounting
screws

Tightening
torque

Electromagnetic
coil

mounting

screws

0
7

kg
m
5
1

ft
Ib

2
Install
the
clutch

assembly
on
the

crankshaft

Note

Key
should
be

set
on
crank

shaft
before

installing
clutch
assem

bly

3

Using
Clutch

Spanner
Wrench

hold
clutch
hub
With

socket
wrench

secure
clutch
hub

securing
bolt

Tightening

torque

Clutch
hub

securing
bolt

1
5

kg
m

II
ft
lb

DISASSEMBLY

1
Remove
two

snap
rings
retaining

bearing
They
are

located
inside
of

clutch
wheel

AC500

Fig
AC
54

Removing

snap
rings

2

Using
Clutch
Wheel

Remover

KV99100700
and
conventional

puller

remove
V

pulley
with

bearings
from

clutch
wheel

KV99100700

AC501

Fig
A
C
55

Removing
clutch
wheel

bearings

3

Using
Bearing
Remover

ST33061000

press
clutch
wheel
bear

ings
out
from
clutch
wheel
Air

Conditioning

9

AC502

Fig
AC
56

Removing
V

pulley
from

clutch

ASSEMBLY

I

Press

bearings
into
V

pulley
with

Bearing
Installer
ST02371000
ST02371000

AC503

Fig
A
C
57

Installing
bearin

2

Install
outer

snap
ring
in

groove

of
V

pulley

3

Using
Installer
KV99100610
and

Stopper
ST33061000

press
clutch

wheel
into
V

pulley

4

Install
inner

snap
ring
in

groove

of
clutch
wheel

t

INSPECTION

Check
friction
surface
of
clutch

for

damage
due
to
excessive
heat
or

excessive

grooving
due
to

slippage
If

necessary
replace
clutch
wheel
and

V

pulley
as
a
set

2
The

clearance
between
V

pulley

and
clutch
wheel
should
be
0
4
to
0
6

mm
0

016
to
0
024
in

If
not

replace
clutch
wheel
assem

bly

AC
35
Installer

KV99100610

2

Stopper

ST33061000

AC504

Fig
AC
58
Installing
clutch
wheel

3
Oil

or
dirt
on
friction
surfaces
of

clutch
wheel
and
V

pulley
should
be

cleaned
with
a

clean
lint
free
cloth
or

suitable
solvent

4

Check
coil
for
shorted
or

opened

lead
wire

Pay
particular
attention

to

grounding
part
of

coil
If
there
is
no

continuity
replace
electromagnetic

coil

AC506

Fig
AC

59

Grounding
point

of
coil

5

If
clutch

assembly
must
lie
re

placed
remember
that

break
in

opera

tion
is

necessary
The
break
in

opera

tion

consists
of

engaging
and

disengag

ing
the

clutch

some

tirty
times

SHAFT

SEAL

ASSEMBLY

The

shaft
seal

assembley
of

this

compressor
is
of
a

simplified
design

yet
tight

sealing
and

long
lasting

REMOVAL

It
is

recommended
that
the

com

pressor
be
removed

from
the

vehicle

for

shaft
seal

replacement

I
Remove

oil
filler

plug
with
D

ring

and
drain

the

compressor
oil

Fig
AC

60

Removing
filler
plug

2
Remove

clutch
Refer
to

Com

pressor
Clutch

Removal

3

Remove

shaft

key
Air

Conditioning

jpL

Y
L

I
i
0

I
I

0

Ace07

Fig
AC
61

Removing
s
wft

key

4

Remove
seal

plate

AC80e

Fig
AC

62

Removing
seal

plate

5

With
the

Compressor
Seal

Puller

pull
out

seal

gland
and
discard

Notes

a

Discard
all

parts
of
the
seal

includ

ing
the
O

ring

b
Do

not
use
a

screwdriver
to

pry

shaft
seal
from
shaft

as

damage
to

shaft

may
result

AC809

Fig
A
C

63
Removing
s
wft
eal

INSTALLATION

1
Clean

shaft
and
seal

cavity
with

clean

lint
free
cloth

2

Dip
seal

gland
in

clean

refrigerant

oil

AC
36
3

Push
seal

assembly

except
carbon

ring
over
end
of
shaft
with

carbon

ring
retainer

facing
out

4
Move

seal

assembly
into

position

on
shaft

1

I

Fig
AC
64

Inserting
wft
al

ass

mbly

5

Place
carbon

ring
in

ring
retainer

so
lapped
surface
is

facing
outward

Note

The
indentions
in
outside

edge

of
carbon

ring
must

engage

driving

lugs
and
be

firmly
seated
in

re

tainer

6
Install
new
D

ring
in

groove
of

seal

plate

Note

Use

refrigeration
oil
to

make
it

adhere
to
surface

7

Space
seal

plate
with

equal
clear

ance
around

shaft
and

insert

cap

screws

8

Tighten
these

screws

evenly

Tightening

torque

Seal

plate
securing

cap
screws

0
7
to
1

0

kg
m

5
to
7
ft

Ib

AC811

Fig
AC
65

8p
cing
01

plate
and

tightening
cap
screws

9

Install

clutch
Refer
to
Com

pressor
Clutch
Installation