check engine light DATSUN PICK-UP 1977 Owner's Guide

Condition

Fuel

gauge

Fuel

gauge
does
not

operate

Pointer
indicates
only

F

position
Body
Electrical

System

Probable
cause

Faulty
tank
unit
or
loose
unit

terminal

connection

pointer
indicates
a
half
level
when
a
35U

resistance
is
connected
between
tank
unit

yellow
wire

and

ground

Faulty
fuel

gauge

Poor

or
loose
cormection

Open
circuit

Faulty
tank
unit

pointer
lowers
below
E

mark
when

igni

tion
switch
Is
turned

off

Faulty
fuel

gauge

pointer
still
indicates
F

position
when

ignition
switch
is
turned
off

OIL
P

RESSURE
AND
CHARGE
WARNING
LAMPS

Condition

Oil

pressure
wamiug

lamp

Lamp
does
not

light

when

ignition
switch
is

set
to
ON

Lamp
does
not

go
out

while

engine
is

being

operated

OIarge
warning
lamp

Lamp
does
not

light

when

ignition
switch
is

set

to
ON

Lamp
does
not

go
out

when

engine
is
started
Probable
cause

Inoperative
oil

pressure
switch
or
loose

switch
terminal
connection

When
switch

yellow
black
wire
is

grounded

warning
lamp
lights

Burnt
bulb
or
loose
bulb

Open
circuit

Lack
of

engine
oil

Oil

pressure
too
low

Inoperative
oil

pressure
switch

Burnt
bulb
or
loose
bulb

Warning
lamp
does
not

light
when

voltage

regulator
white
red
wire
is

grounded

Open
circuit

Faulty

charging
system

BE
20
Corrective
action

Replace
tank
unit
or
correct
terminal

con

nection

Replace
fuel

gauge

Conect
connector
terminal

contact

Replace
tank
unit

Replace
fuel

gauge

Corrective
action

Replace
switch
OJ
correct
terminal
connee

tion

Replace
bulb
or
correct
bulb
socket

Check
oil
level
and
add
oil
as

required

Inspect
engine
oil

pressure
system

Replace
oil

pressure
switch

Replace
bulb

or
correct
bulb
socket

Inspect
charging
system

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

3

Piping

Flared
section
of

high
pressure
and

low

pressure
flexible

hose

Pipe
connections

rvice

valve

4

Evaporator
housing

Jnlet
and

outlet

pipe
connections

Expansionvalve

ELECTRIC
LEAK
DETECTOR

for
the

operational
procedures

refer
to

the
instructions
furnished
with

each
electric
leak
detector

Amount

of

refrigerant
Air

Conditioning

REFRIGERANT

LEVEL
CHECK

SIGHT
GLASS

Sight
glass
is

provided
at
the

top
of

receiver

dryer
One

guide
for
whether

there
is

enough
refrigerant
in

system
is

given
by
observing

refrigerant
flow

through
sight
glass
However
this

method

is
unsuitable
for

judging
the

amount
of

refrigerant
The
correct

refrigerant
level

can
be

judged
by

measuring
t
e

system
pressures
in
ac

cordance
with
the

procedures
de

scribed
Performance
Test

I

Start
the

engine
and
hold

engine

speed
at
1
500

rpm

Almost
no

reftigerant

Check
item

Temperature
of

high
pressure

and
low

pressure
pipes
Almost
no
difference

between

high

pressure

and
low

pressure
side

temperature

Bubbles
flow
continu

ousty
Bubbles
will

disappeu
a
nd
some

thing
like
mist

will

now
when

rerrigeran

is

nearly
gone
State
insightglass

A

I
I

AC256

Pressure
of

system
High
pressure
side

is

abnormally
loW

Repa
ir
Stop

compressor
and

conduct
an
overall

check
Insufficient

High
pressure
side
is

warOl
and

low

pressure

side

is

fairly
cold

The
bubbles
are
seen

at
intervals
of
1
2

seconds

A

r

I

AC257

Both

pressures
on

high

and
low

preS
ure
sides

are

slightly
low

Check
for

gas
leakage

repair
as

required
re

plenish
and

charge

system

AC

16
2

Set

temperature
control
lever
to

maximum

position

3

Set
blower
to
maximum

speed

4

Check

sight
gla
after
the

lapse

of
about
five

minutes
Judge
according

to
the

following
table

AC741

Fig
AC
26

Temperature
control
lever

Suitable
Too
much

refri
crant

High
pressure
side
is

hot
and
low

pressure

side
is
cold
High

pressure
side
is

abnormally
hot

Almost

transparent

Bubbles

may
appear

when

engine

speed
is

raised
and
lowered
No
bubbles
can
be

seen

No
clear
difference
exists
between
these
two

conditions

M

II
I

AC258

Both

pressures
on

high

and
low

pressure
sides

are
normal
Both

pressures
on

high

and
low

pressure
sides

are

abnormally
high

Discharge
reft

gerant

from

service
valve
of

10
11

pressure
side

Notes

a
The
bubbles
seen

through
the

sight

glass
are
influenced

by
the
ambient

temperature
Since
the
bubbles
are

hard
to
show

up
in

comparatively

low

temperatures
below
200C
6S0

F
it
is

possible
that

a

slightly

larger
amount
of

refrigerant
would

be
filled
if

supplied
according
to

the

sight
glass
Be

sure
to
recheck

the
amount
when
it

exceeds
200C

680F
In

higher
temperature
the

bubbles
are

easy
to

show

up

b

When
the

screen
in
the

receiver

dryer
is

clogged
the
bubbles
will

appear
even
if
the
amount
of

refrig

erant
is
normal
In
this
case
the

outlet
side

pipe
of
the
receiver

dryer
becomes

considerably
cold

PERFORMANCE
TEST

Check
for
the
amount
of

refrigerant

in
the

system
can
be

made

by
meas

uring

pressure
on

discharge
side

The

correct
amount
of

refrigerant
is

in
the

system
if

pressure
on
the

discharge
side
is
within

the

specified

range
For
details
refer
to

Perform

ance

Test
described
later

Overcharging
will
show

up
in

higher

pressure
on
discharge
side

COMPRESSOR
OIL

LEVEL

CHECK

The
oil

used
to
lubricate

compres

sor
circulates
into

system
from
the

oil

sump
while

c9mpressor
is

operating

The

efore
to

correctly
measure
com

pressor
oil
the

amount
of
oil

flowing

to

system
must
be

considered
If
a

considerable
amount
of

leakage
of

refrigerant
gas
happens
the

leakage
of

compressor
oil
is
also
considered

There

will
be

no

compressor
oil
leak

age
from
a

completely
sealed

system

When

system
operates
under

satisfying

condition
the

compressor
oil
level

check
is

unnecessary

When

checking
the
level

of
com

pressor
oil
or

when

replacing
any

component
part
of
the

system
use
the

following
service

procedure
This

fa

cilitates
to
return
oil
to

compressor

I

Operate
compressor
at

engine

idling
speed
1
000

rpm
or

below

with
controls
set

for
maximum

cooling
Air

Conditionin
j

and

high
blower

speed
for
10
to

15

minutes
in

order
to
return

compressor

oil
to

compressor

2

Stop
the

engine
and

discharge

refrigerant
of

system
and
then

remove

compressor
from

the
vehicle

3
Remove

compressor
fIller

plug

Drain

compressor
oil
from

compres

sor
oil

sump
and

measure
the

amount

4

Compressor
oil
is

satisfactory
if

the

following
amount
of
oil

remains
in

the

compressor

Residual
oil

S5
to
128

gr
3
to
4
oz

5
Check
the
cleanliness
of
the
oil
If

the
oil
contains

chips
or

other

foreign

material
clean
oil

5ump
with
new

oil

6
Discard
the

used
oil
and

fili
with

the
same
amount
of
new
oil
Add

oil
if

found
less
than
above
amount

Fig
AC
27

Filler

plug

If

compressor
is

inoperative
due
to

faulty
compressor
or

heavy
loss
of

refrigerant
remove

compressor
and

repair
as

necessary
Then

pour
oil

up

to
correct
level
and
install
on

engine

After
above

steps
have
been

complet

ed
recheck
oil
level
drain
oil
to

correct
level
if

level
is

excessively
high

PERFORMANCE
TEST

The
cooling

performance
of
the
air

conditioner

changes
considerably
with

changes
in

surrounding
conditions

Testing
must
be

performed
using
the

correct
method
This

test
is
used
to

judge
whether

system
is

operating
cor

rectly
and

can
also
be
used

as
a

guide

in

checking
for

problems

I

Park
the
vehicle
indoors
or
in
the

shade

AC
17
2

Open
all
the
windows
of
the

vehicle
fully
However

close
the

doors

3

Open
the
hood

4

Connect
manifold

gauge
to

high

and
low
side
service
valves
of
the

system
Refer
to

Handling
Manifold

Ga

uge

5

Set
fan
control
lever
to
maxi

mum

6
Set

temperature
control
lever

to

max
cool

position

7
Start
the

engine
and
hold

engine

speed
at
1
500

rpm

S
After
the
air

conditioner
has
been

operated
for
about
10
minutes

measure

system

pressures
at

high
pres

sure

discharge
side
and
low

pressure

suction
side

9
Measure
the

temperature
of
dis

charge
air
at

outlet

grille

10
Measure
the

temperature
of

capin

11
Measure
ambient

temperature

and

humidity
one
meter
3
3
ft

away

from
condenser
front
Be

careful
not

to

expose
dry
buib

and
wet
bulb

to

direct

sunlight

12
Check
for

any
abnormalities

by

comparing
the
test

results
with
stand

ard

pressure
in
Performance

Chart

Notes

a
The

pressure
will

change
in
the

followi

g
manner
with

changes
in

conditions

When

blower

speed
is

low
dis

charge

pressure
will

drop

When
the
relative

humidity
of
in

take
air
is
low

discharge
pressure

will

drop

b

The

temperature
will

change
in
the

following
manner
with

changes
in

conditions

When
the
ambient
air

temperature

is

low
the
outlet
air

temperature

will
become
low

If
the
test
reveals
that
there
is

any

abnormality
in

system
pressure
isolate

the

cause
and

repair
by
reference
to

the
Trouble

Diagnoses
and
Cor

rections