1977 DATSUN PICK-UP diagram

Operation
of
the
heater
is

control

led

by
two
control
levers
located
on

the
instrument

panel
and
a
hand

op

erated
knob
on
the
center
of
the

heater
unit

The
AIR
LEVER
controls
the
air

intake
valve
and

or
room
valve

by
its

lever

positions
OFF
DEFROST
and

ROOM
through
the
control
cables

The
air
intake
valve
draws
the
fresh

outside
air

from
the
cowl

top
grille

and

supplies
the
air
into
the
heater

unit

The
room
valve
is

located
at
the

bottom
of
the

heater
unit
The
air

coming
through
the
air
intake
valve

opening
is

forced
through
the
heater

core
to
the
room

valve
where
the
air
is

distributed
to
the

floor
outlet
and
or

defroster
outlets

depending
on
the

position
of
the
room
valve

The

VENT
KNOB
is

directly
linked

to
the
vent
valve
which

provides
fresh

air

for
the

passenger
Push
the
knob
all

the

way
in

to

open
the
valve
The
fresh

ventilating
air

comes
out
of
the
heater

center
outlet

The
TEMP
lever
is
a

dual

pur

pose
control
one
is

for

regulating
the

flow
of

engine
coolant

flowing
into
Body
Electrical

System

the
heater
unit
and
the
other
for
the

operation
of
the
fan
motor
When
the

lever
is
in

the
OFF

position
the
water

cock
is

closed
and
the
circulation
of

engine
coolant

through
the
heater
core

stops
When
the
lever
is
slided
to

any

other

position
than
OFF
the
water
cock

opens
in

proportion
to
the

lever

setting
and
allow

engine
coolant

to

flow
into
heater
core

To
control
the
fan
motor

opera

tion

push
or

pull
the
lever
knob
Two

speeds
are

provided
for
the

fan
motor

by
using
a
three

position
switch

FUSE

IOfF
UlwlHI

ON
1

t

f
SWITCH

u

FUSI
BlE

rl
HEATE

R

LINK
SWITCH

is

G
luJ

BATTERY
HEATER
MOTOR

H
EATER
UN
IT

BE868A

Fig
BE
46
Circuit

diagram
of
heater

8E
27

Body
Electrical

System

Circuit

diagram
of
seat
belt

warning
system

Non
California

modela

except
for
Canada

f
FUSIBLE
LINK

p

c

o

BATTERY

California
modela

f

Canada
modela

o

f
FUSIBLE
LINK

F
9

BATTERY

FUSIBLE
LINK

aP

c

BATTERY
IGNITION
SWITCH
FUSE

lOA

@

@I
TIMER

UNIT
I@

I

WARNING
fS

LAMP

l
2

IGNITION

RELAY

FUSE

1
lC
1
lOA

IGNITION
SWITCH

N

IGN
ITION
SWITCH
FUSE

lOA

BE
32
DRIVER
S

BELT
SWITCH

9

ORIVE
R
S

BELT
SWITCH

9

WARNING
r
i

LAMP

I
2
J

DRIVER
S

BELT

SWITCH

9

WARNING

fS

LAMP

I
2
J

Cf
BUZZER

BUZZER

BUZZER

BE689B

Fig
BE
56
Circuit

diagram
of
seat
belt

warning

system

Body
Electrical

System

EMISSION
WARNING
SYSTEM

California

models

CONTENTS

FLOOR
TEMPERATURE
WARNING

SYSTEM

California
models

DESCRIPTION

FLOOR

TEMPERATURE

WARNING
SYSTEM

California
models

DESCRIPTION

The
floor

temperature
warning

system
consists
of

a
floor

temperature

sensing
switch
installed
on

the
vehicle

floor
a

floor

temperature
relay
a

floor

temperature

warning
lamp
and

harnesses

When
the

floor

temperature
rises

to

an

abnormal
level

the

warning

lamp

will

come
on

to
call
the
attention

of

the

driver

i

f
FUSIBLE
LINK

P

BATTERY
IGNITION

SWITCH
BE
43

8E
43
WARNING
LAMP

TROUBLE

SHOOTING
GUIDE
BE
43

BE
44

The

warning

lamp
also
comes
on

during
operation
of

the

starter
motor

permitting
inspection
of

the

lamp
s

condition
The

lamp
goes
out
after
the

engine
starts

Refer

to
Section
EC
for

details

WARNING
LAMP

Bulb

replacement

I

Remove
cluster
lid

2

Twist

warni
ng

lamp
socket

Socket

with
bulb
can
then
be

taken

out

3
Pick

up
bulb
from
socket

IGNITION
RELAY

I
I
4

Installation
is
in
the

reverse
se

quence
of

removaL

Bulb

wattage

Floor

temperature

warning

lamp

17W

Lamp
body
replacement

I
Remove

cluster
lld

2

Disconnect
lead
wire
at
connee

tor

3

Remove
two
screws

retaining

lamp
body

4
Installation
is

in
the

reverse
se

quence
of

removal

FLOOR

I
l

I
SENSOR

RELAY

WARNING
I

LAMP
FLOOR
SENSOR

ON

FLOOR

TEMPERATURE

LOW

OFF
FLOOR

TEMPERATURE

HIGH

7

BE697B

Fig
BE
64
Circuit

diagram
of
floor

temperature
warning

system

BE
43

The

refrigerant
within
the

thermo

bulb

changes
in

pressure
through
the

super
heat

condition
of

vaporized
re

frigerant
gas
which
comes
out
of
the

evaporator
causing
the

deflection
of

the

diaphragm
The
lift

of
the

ball

valve
attached
to
the

diaphragm
is

changed
by
the
deflection
of
the
dia

phragm
thus

controlling
the
amount

of

refrigerant
passing
the

orifice

ELECTRICAL
CIRCUIT

DESCRIPTION

The

electrical
circuit

of
the
air

conditioner
consists
of
four
switches

two

relays
a
solenoid
valve
a
fan

motor
and
a

compressor
magnetic

clutch
Air

Conditioning

Diaphragm

Orifice

Valve
ball

AC729
4

Sensing
bulb

Fig
A
C
6

Expansion
value

The

following
wiring
diagram

pro

vides
a

complete
description
of
the

whole
circuit

When
the

ignition
switch
and
the

fan
switch
are
ON
the
main

relay
is

activated

causing
battery
power
to

flow

through
the
fan
motor
and
the

magnetic
clutch
The

magnetic
clutch

is

activated

by
the
thermo
switch

AC
5
000

l

1
Motor

2
Fan

3
Lower

case

4

Cooler
duct

5

Evaporator

6

Expansion
valve

7

Upper
case
8
Resistor

9

Main

relay

10
Thermo
switch

II
Cable

clamp

12

Cable

13
Harness

AC725

Fig
AC
7

Cooling
unit

pressure
switch
and

compressor
relay

The

blower
motor
fan

speed
is

con

trolled

by
the
fan
switch
and
resistor

The
solenoid
valve
is

also
activated

This
in
turn

causes
the

fast
idle
control

device
F
l

C
D
to
increase

engine

speed
when
the

vehicle
is

at
rest
with

the

engine
ON

1
I

6

I

BA

RY

i
Air

Conditioning

BW
c
J

BW

n
B

m

00
L
ELECTRIC

FUEL
PUMP

oB

tl

b@

L

t

FROM
LIGHT

SWITCH

c
J

LW
2
L

rRL
fZP
W

I
FUSE
15A

J
D
CJ
B

1
COMPRESSOR
RELAY
B

GL
I

lL

GL1J
ILLUMINATION

CONTROL

RHEOSTAT

3

ILLUMINATION

LAMP

I

I
MAIN
RELAY

FAN
SWITCH

I

r

1

UE
H

I

I
THERMO

SWITCH

COLOR

CODE

@

IC
PRESSU
1

rlTCH

D
D

G
c
J
oc

I
m

f
F
I
C
D

SOLENOID

COMPRESSOR

FUSE
LR

I

BW
O

W

ov
J

I

IG
0

0

OVJ

AC

6
B

BW

L

LW

LR

W

G

GL

RL
Black

Black
with
white

stripe

Blue

Blue
with

white

stripe

Blue
with
red

stripe

White

Green

Green
with

blue

stripe

Red
with
blue

stripe

IG

BW
t
1

n

L

IGNITION
SWITCH

AC727

Fig
A
C
B

Wiring
diagram
of
air
conditioner

system

Air

Conditioning

REMOVAL
AND
INSTALLATION

COMPRESSOR

REMOVAL

INSTALLATION

IDLER
PULLEY

FAN
BELT

TENSION
ADJUSTMENT

REMOVAL
AND
INSTALLATION

INSPECTION

COOLING
UNIT

REMOVAL
AND
INSTALLATION

DISASSEMBLY
AND
ASSEMBLY

INSPECTION

RECEIVER
DRYER
AND
PIPING

COMPRESSOR

REMOVAL

I
Remove

battery

2

Disconnect

compressor
lead
wire

at
connector

3
Loosen
idler

pulley
lock

nut
then

adjusting
bolt
Remove

compressor

drive
belt

from

compressor
pulley

AC477

Fig
AC
28

Removing
drive
belt

4

Discharge
system
Refer
to
Dis

charging
System
under
General
Service

section
CONTENTS

AC
25

AC25

AC26

AC
27

AC
27

AC27

AC
27

AC27

AC
27

AC
2B

AC
29

AC
29
REMOVAL

AND
INSTALLATION

INSPECTION

WIRING

HARNESS
AND

COMPONENTS

WIRING
DIAGRAM

MAINTENANCE

MAIN
RELAY

COMPRESSOR

RELAY

FAN
SWITCH

RESISTOR
FOR
FAN
SWITCH

THERMO
SWITCH

F
I

C
D
SOLENOID
VALVE
AC29

AC29

AC30

AC30

AC31

AC31

AC31

AC31

AC32

AC32

AC
32

5
Remove
flexible
hose

fixing
plate

and
disconnect
low
and

high
pressure

flexible
hoses
from

compressor

Notes

a
Use
two

wrenches
when
disconnect

ing
pipe

joints

b

Plug
flexible
hose
and

compressor

joint
openings
immediately
after

disconnection
to

prevent
entry
of

dust
moisture
laden
air
etc

Fig
AC
29

Disconnecting
ftexible

hoses

from
compressor

6
Remove

bolts

securing
fuel
tube

to

compressor
attachment

AC
25
Y
1

L

AC744

7
Remove
four
bolts

securing
com

pressor
to
its
bracket

Compressor
and

attachment

can
now
be
detached
as
an

assembly

Notes

a
There
are
a

total
of
four
bolts
two

on

upper
side
of
bracket
and
two

on
lower
side
of

compreSsor

Loosen

upper
bolts
and
remove

lower
bolts
When

removing
upper

bolts

securely
hold

compressor

with
one
hand

b
When

installing
temporarily
tighten

upper
bolts
then

tighten
lower

bolts

Ll1
1t

W
l
THERMO
SWITCH

I

I
Air

Conditioning

WIRING
HARNESS
AND
COMPONENTS

WIRING
DIAGRAM

BW
c
J

ii

1
l
BW

La

GL

FROM

LIGHT
SWITCH

CJ

Id

lW
f
8
L

rRl
@
W

I
FUSE
15A

1
J
D
CJ
B

B

o

J
I

B

y
i

jqt
0

noc
I
no
vi

1
J

mcl
y

yldru
ao
11
jblr
J

H
WJ1

q

2f
br
r
t

lH

iot
f1
tH
o
hm

I
l
i
I

1
rf
l
t
f
r

dt
ll
II

h
J

IiJ
l
I

d
hi

s
n

Jq

DDj
G
w
TG
r

i

i
It
U
JI1
GH
Jdf
J

t

ggo
J

10
lHohfth

gniJuo
lUb
Jl
VUlt
l0
H
2

1
19
i
tl
b

wt
IO
t
l
lo
J
I
l

l

to
tJ
b

YR
lStO
Y1

1
t
J
I

FUSE

I
II
nlWI

I
bn
f
w
1

U
QI
llnio

fiq
ni

I
tsH
W
tflt
fli
htTin
lnl

O
J
11

IJ
i
Ji

fjI
i
i
11

i
ltll
ii
A
jll

I
I

I
gm
J
lIno
tl

Jl

JIIgiJ
l

1I0U
mflu
J
l
tllU
lJU

8
f
r
j

d

j
J
l1
Jlt

d
HInO
IG

to
l
VFJ
r1
rjJ
1

J
h
nI
0
i

IEvUID
l

il
1
i2
1

MN
k
B

gg

liii

gg
1

B
J

Ii
i
ELECTRIC

FUEL
PUMP

@
ILLUMINATION

CONTROL

RHEOSTAT

COLOR
CODE

B
Black

BW
Black
with
white

stripe

L
Blue

LW
Blue
with
white

stripe

LR
Blue
with
red

stripe

W
White

tll
G

GreeMnQ
r
iC
O
1

r

J
l
GL
Green
with
blue

stripe

R
L
Red
ith
blue

stripe

201011

lIt
J
m

I

W

tfli

I
o

lUll

IJ

Ub
OW

If
U
d

l

Q
I

ni

IGNITION
SWITCH

WIJIJJOO
W
l

Iuul
vomo
C

held

l

Jlb
vi
ia
1
1

tnd
15
W
le
llt

J
l

nq
LnJ

J
I
1

luil

mpHO
ibGt
L
D
lb

tldmoGl
nG
III
rbliw7
tHO

b
b
1
AC727

ns
1
j

fJ
l
YI
l
mtl
m
0
I

lfi
IO
fI
l

jg
h5
4
MjVj
IJC
p

i
W
i

1q

T

h
M
U
lAIIl

j
ro

o

i

e
w

J
lPUMP

Q
O
WIRING
DIAGRAM

I
IIITSlDl

AI

ij
L

rn

H

r

IJ
rC

jil

11
i

Jl
o
J
11
Il

r
oiiil
IIrTllI

ii

i
t
1

i

U
3
E

1
1
l

r

5

fl

U
Eel

I

k

1

J
l
II

I
L

L

It
1

I
c

1

QbJ

E
f

t
d
E

1

I
it
F
O

SE

FF
l
vIII

i
I

J

t

E

rBtr
irK

nrr
t

UFo1

i

Joftl
u

f
l

1
1
O

tn

L

J

V
L
r

j

I
rmIw

nil
fflI

ml
l

li

JJ
n
E
CC

Mji
i
l

b

WJ
r
D

IIL
I
l

C
II
i

i
L
T

l

L
I

I
r

0

in
i

M

mB
I

llC
OUIOD

1
L

11

I

rL
ii
fH

IURf

L
I

i

J

l
T
SOlENOID

II

f
n
I

r

0

Ol
NOI0

y

lI
Ullt
lt
UIl

ll
ll

Dill

lfT
l
l

MNIMG
P

l
lI
S

r

HOUIUlTON

l
cP
HA
AAD

wd

I
ii
ii
I

r
J
L
P
It
J

1
o

o

I
III

aU

tie

1AN
UNIT

GAUGE

e
l
J

I
L
i

I
L

M

W1

ii
Ir
1

MhROl
IT
I

IllUMINJflON
l
P

I

I

I
I

Ii
r
I

W

IW
JI

t
J

l

1

1

M
I
l

IlJi

i
J
W

rElI

C

rU
T
1

1I0Nr@J
LillI

l

a

J
J

WJ

H
E

Jr

G

j
ONlJ
P

1
L

J
II
IPH
I
1GHl

r
Rl
JILlUMINAlION

r
l
lllU
IM
1I0N

l
L
CON
OllH
OS
Jl
i

P
Fll
S
11lII1T

Gl

0
d1

EI

1
1II0NS

II

g
11

IIO
l
OISlATIO

Alr
tl

SIST
lI1

l
SfJ

II
ITIO
COll

CAlIrCl
IA

I
1l0nfl

J

rm

n

I
L

n

1

t

LI

iElr
I

Ct
@

C
I

l

I
11

l
@
1
1
B

w

l

V

TilBlJ101
r
i
I

J

J

1
D

f

J1J1

mlSl
II1

IQClTIO
ICOIL

QlI
CALlFO
I
1l00ELS

iGI
L
f

w

Ih
rUSE
IOCI

3
1
w
1S1

t
IDA
1

1

e
o

rL
l
r

e
COIl
CT

I
1
ll1t

I
lSII
lo

CIlIr
lSII
WI
aM
ItlII
E
151

ISA

iO

J

r
g
l

l

H

g
I

P
tlII
till

I
PI
to
bo
1Jo

lIool
a

1

ts
lli
lo
Ct

I

Ull

1171

IlCl
lJP

t
J
L1CE
t

rt
VLA1II

W

I
TlIl

IIl
ATIO

1

1

M

JlI
SIOE

lllltlUlAII

lDTF

w

on

LOlTGllI1

r
1

lIOC
JII
tTD
C
lW
tlKlI
CCNlEClD

ORIlAl
ttOSlO
I
IlAL

FIJrNIA

OIHAur
ll
1
1l00m

F
II

OIlATlt
ISIQIj

ll
U
SMI
llO

ItlUlCIJIjQIlICJO

lllOI
fLAlI
UilTIOllS

IIO
IITlOIswntH

U
MTlIlGSWlICH

lUUlJlXtlftO

lIOOISQ
Dll
O

TI
Il
Ult
ll

W
l
UAllD
SWITCH