1977 DATSUN PICK-UP heater

Body
Electrical

System

Horn
switch

The
horn
switch
is

integral
with

the

turn

signal
and
dimmer
switch
as

sembly
Remove
switch

assembly
as

outlined
in
Turn

Signal
and
Dimmer

Switch

IGNITION
SWITCH
BE861A

Fig
BE

3
I

Removing
ignition
switch

REMOVAL
AND

INSTALLATION

I
Disconnect

battery
ground
cable

from

battery

2
Unscrew
and
remove
escutcheon

from
the
front
of

ignition
switch

3
Withdraw

ignition
switch
and

wiring
assembly
with

spacer
from

shell
cover
as
shown
in

Figure
BE
3

4

Disconnect
wiring
connector

from
the
back
of

ignition
switch

5

Replace
ignition
switch
with
a

new
one

6
Connect

ignition
switch
to

wiring

connector

7

Position

ignition
switch
to
shell

cover

opening
install
and

tighten

escutcheon
and
secure
ignition
switch

to
shell
cover
R
terminal

1G
terminal

ST
terminal

B
terminal

8E

22
1

Voltage

regulator

2
Horn

relay

3

Headlamp
relay

4

Ignition
relay
California

only

5

Auto
choke
heater

relay

6

Compressor
relay

Au
conditioner

equipped
model

7

Floor
sensor

relay
California

only

8
Inhibitor

relay
Automatic

tran5mission

only

INSPECTION
BE683B

Fig
BE
30

ContInuity
test

Test

continuity

through
ignition

switch

by
using
test

lamp
or
ohm

meter

C

A
terminal
TERMINAL
0

F

F

B

IG

ST

A

R
KEY

FOSITlON

t

1

o

j
u

u

I

I
A

C

C

Fig
BE

32

Ignition
witch
BE6848

INSTALLATION

I
Position
clock
to

cluster
lid
and

install
three
screws

2

Connect
three
wire
connectors
of

clock

to
each
connection
two
to

combination
meter

printed
circuit
one

to
instrument
h
ness

wiring

3

Install
cluster
lid
to
instrument

panel

4

Connect
battery

ground
cable

HEATER

DESCRIPTION

@
Body
Electrical

System

Fig
BE
44
Clock

1
Defroster
nozzle
L
U

2
Deflor
tcr
duct
L
R

3
Heater

control

4

Resistor

5
Heater
motor

6
Heater
case
7
Ventilator
knob

8
Heater
core

9
Conuol
cable

clip

10
Heater
cock

11
Defroster

duct
R
H

12
Defroster
nozzle
R
H

BE687B

Fig
BE
45
Heater
comtruction

BE

26

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

AIRFLOW

OFF

VENTILATING

Push
Vent
valve

Heater
core

c

n

e
NlL
fAl

u

c
J
u
IUl

g

Push

Pull

DEFROSTING

VENTILATING
HEATING

0
tTIlsl

IU
lI

D
WI
Push
Pull

g

IIt
J

L

I
I

Pull

Pull

DEFROSTING

HEATING

n
C
IU

n

HU

I
ff

UIUI

C
J

CIl

JIlT

Ill

Pull
J

11

Pull

BE397

Fig
BE

47

Airflow

8E

28

HEATER
UNIT
ASSEMBLY

Removal

L
Disconnect

battery
ground
cable

2

Drain

engine
coolant

3

Remove
defroster
hoses

4

Remove
three

cable

retaining

clips
and
disconnect
control
cables

from
valves
and
water

cock

5

Disconnect
two

fan
motor
lead

wires
from
each
connector

6
Disconnect
two
resistor

lead
wires

from
each
connector

7

Disconnect
water
hoses
from
core

and
water
cock

8

Remove
three

heater
housing

mounting
bolts
and

dismount
heater

unit
from
vehicle

Installation

1

Position
heater
unit
under
instru

ment

panel
and
install
three
heater

unit

securing
bolts

2

Install
water
hoses

3
Position
heater

control
cables
to

room
valve
air
intake
valve
and
water

cock

4

Adjust
control
cable

length
for

proper
operation
as

outlined
in

Adjust

ment

5
Connect
fan
motor
wires
and

resistance
wires

to
each
connector

plug

6

Install
defroster
hoses

7

Connect

battery
ground
cable

8
Fill

cooling

systeIT

9
Run

engine
at
2
000

rpm
with

AIR

lever
in

the
HOT

position

Make
sure
that

engine
coolant
is
fIlled

up
to
correct
level

HEATER
CORE

Removal
and
installation

L

Drain

engine
coolant

2
Remove
defroster
hoses

3
Disconnect
water
hoses
from
inlet

and
outlet

pipes
of
heater
core

4

Remove
four

clips
and
front

cover
Body
Electrical

System

BE869A

Fig
BE
48

Removing
front
cov
r

S

Withdraw
heater
core
from
heater

housing

BE870A

Fig
BE
49

Removing
heater
core

6

Install
heater
core
in

the
reverse

sequence
of

removal

FAN
MOTOR

Removal
and
Installation

L
Dismount
heater
unit

assembly

from
vehicle

as
outlined
in
Removal
of

Heater
Unit
Assembly

2
Remove
nine

spring
clips
and

disassemble
heater

housing

3
Remove
fan
from
fan
motor

4
Remove
fan

motor

retaining

screws
and
fan
motor

S
Assemble
heater

housing
and
in

stall
heater
unit

to
vehicle
in
the

reverse

sequence
of
removal

as
out

lined
in

Installation
of

Heater
Unit

Assembly

I

CONTROL
ASSEMBLY

Removal
and
Installation

I
Remove
three
cable

retaining

clips
and
disconnect
control
cables

from
valves
and
cock

BE
29
2

Disconnect
three
lead
wires

from

each
connector

plug

3

Remove
radio
bezel
from
the

front
of
radio

following
instructions

in

steps
I

to
3
in

Removal
of
Radio

4

Remove
heater
control
knobs
and

heater

bezel

5

Remove
two

retaining
bolts
and

heater
control

assembly

6
Install
control

assembly
in
the

reverse

sequence
of

removal
When

connecting
control
cables

to
valves
and

cock

adjust
control
cable

length
as

outlined
in

Adjustment

ADJUSTMENT

AIR
lever

L
Move
AIR
lever
to
the
DEF

position

2

Open
air
intake

valve
and

connect

control

cable
to
air
intake
valve

3

Clip
control
cable
with
cable

re

taining
clip

Fig
BE
50
A
iT
intake
valve

4
Pull
room
valve

upward
and
con

nect
control
cable
to
room
valve

5

Clip
control
cable
with

cable
re

taining
clip

BE871A

Fig
BE
51

Room
valve

CD
m
Cl
@
D
@

I

j

1
To
instrument
harness
IS
To
battery
30
To
check
connector

2
To
full
transistor
amplifier
16
To
fusible
link
3t
To
headlamp
L
U
type
2

California
models
only
17
To
engine
harness
No
2
32
To
sido
marker
lamp
L
B

3
To
hood
switch
18
To
alternator
33
To
front
combination
lamp
L
H

4
To
engine
compartment
lamp
1
9
To
front
combination
lamp
R
n
34
To
horn
Low

ll
l
S
To
washer
motor
20
To
headlamp
R
H
type
2
3S
To
horn
High

l
l
0
6
To
auto
choke
heater
relay
1
To
side
marker
lamp
R
n
36
To
B
C
D
D
cut
olenoid
California
models

7
To
detector
dri
e
counter
22
To
headlamp
R
B
type
1
only

Non
Califunia
model
except
for
Canada
23
To
ground
37
To
block
tcrminal
distributor
California

8
To
ignition
relay
California
models
only
i4
To
thermal
transmitter
models
only

9
To
floor
sensor
relay
California
modeb
only
is
To
distributor
Non
California
models
only
38
To
ignition
coil
Non
California
models
only

n
10
To
inhibitor
relay
A
T
only
26
To
8
C
D
D
cut
solenoid
Non
California
39
To
condenser

t
II
To
head
lamp
relay
models
only
40
To
ignition
coil
and
resistor
@

12
To
horn
relay
27
To
fuel
cut
solenoid
California
models
only

OJ
v

m
13
To
voltage
regulator
28
To
auto
choke
heater

g
e
14
To
cooler
cable
29
To
headlamp
L
R
type
1

OJ
to

o
Q
m
r0

C
1
i

Ql
CIl
Il
l
3

m
J
c
@
@
r

1
I
I

I
II

U
j
J

r
U

I
IT

L
U
L
L

@

Qj
flll
I

1

I
I

1

lL

to
t
l

Q
1
To
room
Jamp
cable

2
To
light
switch

3
To
fuse

4
To
tachometer
or
clock

5
To
hazard
flasher
unit

6
To
stop
lamp
switch

7
To
ignition
switch

8
To
hazard
switch

9
To
tU
and
dimmer
switch

10
To
check
connector

11
To
AMP
M
T
only

11
To
combination
instrument

Non
California
mode15
except
for
Canada

13
To
combination
meter

14
To
flasher
unit

IS
To
kickdown
switch
AfT
only

16
To
hand
brake
switch

17
To
heater
motor

18
To
illumination
control
rheostat
19
To
wiper
switch
light
switch
illumination

lamp

20
To
wiper
switch

21
To
cigar
lighter

22
To
heater
control
illumination
lamp

23
To
radio

24
To
heater
control

25
To
belt
and
E
G
R
warning
lamp

Non
California
models
or
floor
te
peratuJe

California
models

26
To
heater
control
illumination
lamp

27
To
buzzer

28
To
belt
warning
timer
U
S
A
Olodels

29
To
indicator
lamp
AfT
only

30
To
cooler
harness

31
To
wiptr
motor

32
To
door
switch
R
H

33
To
engine
compartment
harness

34
To
floor
harness

E
m

S
@
o
J
o

Q
m
CD
n

Ql
en
I
i
3