light DATSUN 210 1979 Owners Manual

Air

Conditioning

6
Loosen
the
connection

at
the

center

fitting
of

manifold

gauge
for
a

Clockwise
few
seconds
to

purge
air
inside

charg

ing
hose
See

Fig
AC
14

Counterclockwise

j

3

@

I

Can
tap
handle

2

ChlcginS
hose

3
Needle

4

Refrigerant
can

AC246

Fig
AC
13
Can

Top

Purging
air

R

12

To

L9w
pressure

service
valve
AC247

Fig
AC
14

Purging
Air

Ta

High
pressure

service
valve

f

r

AC181A

Fig
AC
15

Discharging
System

AC
ll
DISCHARGING
SYSTEM

The

pressurized
refrigerant

gas
in

side

system
must
be

discharged
to
a

pressure
approaching
atmospheric

pressure
prior
to

evacuating
refrigerant

inside

system
This

operation
should

be
also
made
to

pennit
safe
removal

when

replacing

system
components

A
Close

high
and
low

pressure

valves

of
manifold

gauge
fully

2

Connect
two

charging
hoses
of

manifold

gauge
to

their

respective

service
valves

WARNING

Securely
connect

high
pressure
dis

charge
service
valve
to
that
of

manifold

gauge
with
a
hose
also

connect
low

pressure
suction
serv

ice
valve
to
that
of
manifold

gauge

For

locations
of

high
and
low

pres

sure

discharge
and
suction
service

valves
see

Fig
AC
29

3

Open
both
manifold

gauge
valves

slightly
and

slowly
discharge
refriger

ant
from

system
See

Fig
AC
15

WARNING

Protect

fingers
with
cloth

against

frostbite

by
refrigerant
when
con

necting
the

charging
hose

to
the

service

valve
or

disconnecting
it

therefrom

Nole
Do

not
allow

refrigerant
to
rush

out
Otherwise

compressor
oil
will

be

discharged
along
with

refriger

ant

EVACUATING

SYSTEM

I

Connect

high
and
low

pressure

charging
hoses
of
manifold

gauge
to

their

respective
service
valves

of

sys

tem
and

discharge
refrigerant
from

system
Refer
to

Discharging
System

WARNING

Securely
connect

high
pressure
dis

charge
service
valve
to
that
of

manifold

gauge
with
a
hose
also

connect
low

pressure
suction

servo

ice

valve
to
that
of
manifold

gauge

For

locations
of

high
and

low

pres

sure

discharge
and
wction
service

valves

see

Fig
AC
29

HALIDE
LEAK
DETECTOR

Since
the

propane
leak
detector
and

butane
leak
detector
are
the
same
in

respect
to
their

operation
this
section

describes
the

operation
of
the

propane

leak
detector

The

copper
screen
is
heated

by
the
Air

Conditioning

burning
of

propane
Refrigerant
gas

decomposes
to
color
the

flame
when
it

contacts
the
heated

screen
The

gas
to

be
checked
is
drawn
into
the

sampling

tube
and

sent
out
to
the
burner
A

refrigerant
leak
can
clearly
be

detected

by
variations
in
the
color
of
the

flame

1

Copper
reaction

plate

2
Flame

adjusting
lines

3
Burner

4

Sampling
tube

5
Strainer

6
Gas
bomb

7

Flame

adjuster

AC010

Fig
AC
22
Checking
for
Leaks
4

The
flame
will
be

almost
colorless

when
there
is
no

refrigerant
gas
being

burned
When
there
is

a
small

refriger

ant

gas
leak
the
flame
will
be

green
or

yellowgreen
When

refrigerant
gas
leak

age
is

large
the
flame

will
be
brilliant

blue
or

purple
Since
the

color
of
the

flame
will
be

yellow
when
dust
is

being
burned

or
there
is

aging
scale
on

copper
reaction

plate
always
keep
the

strainer

of

sampling
tube
and
reaction

plate
clean

5

Major
check

points

l
Compressor

Compressor
shaft
seal

rotate
the

compressor
by
hand

Flexible
hose

connections

Front
and
rear

head

gaskets

Service
valve

2
Condenser

Condenser

pipe
fitting

Condenser
inlet
and

outlet

pipe

connections

3
Refrigerant
lines

Flared
section
of

high

pressure
and

low

pressure
flexible
hoses

Une

connections

4

Evaporator
housing

Inlet
and
outlet
line
connections

Expansion
valve

Propane
type
Butane

type

ELECTRIC
LEAK
DETECTOR

NO
LEAK

Greenish
blue
Pale

blue

For
the

operational
procedures

SMALL
LEAK
Yellow

Bright
blue
refer

to
the
instructions
furnished
with

LARGE
LEAK

Purple
Vivid

green
each
electric
leak
detector

Discharge
refrigerant
in
one
or

two
seconds

to
ascertain

that

system

has

a
sufficient

pressure
needed
for

leak
detection

Charge
with
0
4

kg
0
9

Ib
of

refrigeranl
if

necessary

2

Light
leak
detector

Adjust
the

height
of
the
flame
between

flame

adjusting
lines
at
the

top
and
bottom

of
combustion
tube

A
reaction

plate

will

immediately
become
red
hot

3
Place
the
end
of

sampling
tube

near
the

point
of
the

suspected
leak
in

system

Note

a
Since

refrigerant
gas
is

heavier
than

air
small
leaks

can
be

easily
detect

ed

by

placing
sampling
tube
direct

ly
below
the
check

point
b
Suitable
ventilation
is

required
If

refrigerant
gas
is

mixed
with
the

surrounding
air
leak
detector
will

always
indicate
a

response
and

detection
of
the
actual
leak
will
be

difficult

c
Never

hold
leak
detector
at
an

angle

WARNING

a
Never
inhale
the
fumes

produced

by
combustion

of

refrigerant
gas

since

they
are
toxic

b
Never
use
halide
torch
in
a

place

where
combustible
or

explosive

gas
is

present

AC
15
REFRIGERANT

LEVEL
CHECK

SIGHT

GLASS

Sight
glass
is

provided
at
the

top
of

receiver

drier
One

guide
for
whether

there
is

enough
refrigerant
in

syst
m
is

given
by
observing
refrigerant
flow

through
sight
glass
However
this

method
is
unsuitable
for

judging
the

aJTlount
of

refrigerant
The
correct

refrigeranl
level
can
be

judged
by

measuring
the

system
pressures
in

ac

cordance
with
the

procedures
as
de

scribed
in
Performance
Test

1

Start
the

engine
and
hold

engine

speed
al
1

500

rpm

2

Set
AIR
lever
to

AlC

position

I

I

3
Set

temperature
lever
to
max

imum

cold

position
Air

Conditioning

4

Sefblower
to
maximum

speed

S

Check

sight
glass
after

the

lapse

Almost
no

refrigerant

Check
item

Temperature
of

high
prenure

and
low

pressure
lines
Almost
no
difference

between

high
presswc

and

lowpressufC
side

temperature

State
in

sight
gl
ltS3
Bubbles
flow
continu

ously
Bubbles
will

disappear
and
some

thing
like

mist
wiD

flow
when

rerrigel
l
llt

is

nearly

gone

AC256

Pressure
of

system
High
pressure
side
is

abnormally
low

Repair
Stop
compressor
and

conduct
an

overall

check

Note

a
The
bubbles
seen

tbrough
the

sight

glass
are
influenced

by
the
ambient

tempemture
Since
the
bubbles
are

bard
to
show

up
in

comparatively

low

tempemtures
below
200C
680

F
it
is

possible
that
a

slightly

larger
amouot
of

refrigemot
would

be
filled
if

supplied
according
to

tbe

sight
glass
Be

sure
to
recheck

the
amount
when
it

exceedS
20
C

680F
In

higher
tempemture
tbe

bubbles
are

easy
to
show

up
Insufficient

High
pressure
side
is

warm
and

low

pressure

side
is

fairly
cokt

The
bubbles
are
seen

at
intervals
of
1
2

seconds

AC257

Both

pressures
on

high

and
low

pressure
sides

are

slightly
low

Check
for
gas

leakage

repair
as

required
re

plenish
and

chaxge

system

b
Wben
the
screen
in
tbe
receiver

drier
is

clogged
tbe
bubbles
wiD

appear
even
if
the
amount
of

refrig

erant
is

nonnaL
In
this
case
tbe

outlet
side

pipe
of
tbe
receiver
drier

becomes

considembly
cold

AC
16
of

abOut
five
rilintJtes

Jullgeaccording

to
the

following
table

Suitable
Too
much

refrigerant

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
these
two

conditions

nl

AC258

Both

pre55ures
on

high

and
low

pressure
sides

are

normal
Both

pressures
on

high

and
low

pressure
sides

are

abnonnally
high

Discharge
refrigerant

from
service
valve
of

low

pressure
side

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
i
within
the

specified

range
For
details
refer
to
Trouble

Diagnoses
and
Corrections
for

per

fannance
test

Overcharging
will
show

up
in

higher

presstJre
on

discharge
side

COMPRESSOR

OIL
LEVEL
CHECK

The
oil
used
to
lubricate

compres

sor
circulates
into

system
from
the
oil

sump
while

compressor
is

operating

Therefore
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

facio

litates
to

return
oil
to

compressor

1

Operate
compressor
at

engine

idling
speed
I
OOO

rpm
or
below

with

controls
set
for

maximum

cooling

and

high
blower

speed
for
10
to
15

minutes
in
order

to
return
com

pressor

oil
to

compressor

2

Stop
the

engine
and

discharge

refrigerant
of

system
and
then

remove

compressor
from
the

car

3

Remove

compressor
filler

plug

Drain

compressor
oil
from

compres

sor
oil

sump
and
measure
the
amount

AC742

Fig
AC
23
Filler
Plug

4

Compressor
oil
is

satisfactory
if

the

following
amount
of
oil
remains
in

the

compressor

Residual
oil

140
to
220
cc

4
7

to
7
4
US
fl
oz

4
9
to
7
7

Imp
fl
oz
Air

Conditioning

5
Check
the

cleanliness
of
the

oil
If

the
oil
contains

chips
or
other

foreign

material
clean

oil

sump
with
new
oil

6
Discard
the
used
oil
and
fill
with

the
same

amount
of

new
oil
Add

oil
if

found
less

than
above
amount

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

com

pleted
recheck

oil
level
drain
oil

to

correct
level

if
level
is

excessively
high

CAUTION

a
The
oil
should
not
be
transfused

from
a
container
into
another
as

the
failure
will

possibly
cause

moisture
to
mix
with
the
oil

b
The
used
oil
should
not
be
returned

into

a
container

c
The
oil
should
not
be
used
if
its

state
of

preservation
is
not
clear

enough

PERFORMANCE
TEST

The

cooling

per
ormance
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

guiqe

in

checking
for

problems

1
Park
the

car
indoors
or
in
the

shade

2

Open
all
the
windows

of
the
car

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

Gauge

5

Set
air
lever
to

AIC

position

6
Set

temperature
lever
to
maxi

mum
cold

position

7

Set
blower
to
its

highest

speed

8
Start
the

engine
and
hold

engine

speed
at
1
500

rpm

9
After
the
air
conditioner
has
been

operated
for
about
10
minutes
meas

ure

system
pressures
at

high
pressure

discharge
side
and
low

pressure
suc

tion

side

10
Measure
the

temperature
of
dis

AC
17
charge
air
at
the

center
outlet

grille

11
Measure

the

temperature
and

humidity
of
the

evaporator
in
take
air

at

the

recirculating
air
inlet

of
the

evaporator

12
Measure
the

temperature
and

humidity
of
the
ambient
air
at
a

point

I
m
3
3
ft

front
of

condenser

However
a

dry
bulb

and
wet
bulb

must
not
be

placed
in

direct
sunlight

13

Check
for

any
abnormalities
by

comparing
the
test
results

with
stand

ard

pressure
Refer
to

Performance

Chart

Note

a

The

pressure
will

change
in
the

following
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
Refer
to
Trouble

Diagnoses
and
Corrections

REFRIGERANT

LEAKS

If
leaks
are

noticeable
leaky
parts

should
be

repaired
Then
system

should

be
fIlled
with

refrigerant

CAUTION

00

not

operate
compressor
with

refrigerant
level

excessively
low

If
this
caution
is

neglected
a
burnt

compressor
will
result
since

heavy
loss

of

refrigerant
usually
indicates

heavy

loss
of

compressor
liil

I

f

system
has
been

exposed
to

atmosphere
for

an
extended

period
of

time

I
receiver

drier
must
be

replaced

If
leaks
are

slight
and

no
air
is

present

in

system
add

refrigerant
as

necessary

To
detect
leaks

refer
to

Checking

for
Leaks
Here
is

how
leaks

are

stopped

I

Check

torque
on

the
connection

fitting
and
if
too
loose

tighten
to
the

proper
lorque
Check
for

gas
leakage

with
a
leak
detector
Air

Conditioning

2
If

leakage
continues

ven
after

the

fitting
has
been

retightened
dis

charge
refrigerant
from

system
disc
on

net

the

fittings
and

check
its

seating

face

for

damage

Always
replace
even

if

damage
is

slight
J

Check

compressor
6il

and
add
oil

if

required

4

Charge

refrigerant
and
recheck

for

gas
leaks

If

no
leaks
are
found

evacuate

and

charge
system

SERVICE
PROCEDURES

FAST
IDLE

ACTUATOR

ADJUSTMENT
OF

IDLE
SPEED

Engine
model

Transmission
When

A
C
is
OFF
When
A
C
is
ON

F

LCD
is

actuated

Manual

700

rpm
800

rpm

A14
A15

Automatic
650

rpm
800

rpm

at
D

position
at
N

position

The
fast
idle

control
device
is
used

on

cars

equipped
with

an
air

condi

tioner
to
raise
the

idle

speed
auto

matically

Use
the

following
procedures
when

adjusting

1
Run

engine
until
it

reaches

oper

ating

temperature

2

With
air
conditioner
in

OFF

when

compressor
is
not

operated

make

sure
that

clearance
e
between

levers
A
and

8
is

more
than

J
mm

0
12
in

If
clearance
C
is

less
than

J

mm
0
12
in

loosen
cable
lock

screw
and

push
down

on
lever
A

so

that
clearance
C
is

more
than
J
mm

0
12
in

3
Make
sure

that

engine
is
at
cor

rect
idle

speed

4

With
air

conditioner
in

ON
when

F

LC
D
is
actuated

set

engine
speed

to
800

rpm
using

following
procedures

as
a

guide

I
Turn

adjusting
screw
until
en

gine
speed
is
800

rpm

On
cars

equipped
with
automatic

transmission

make
this

adjustment

with
shift
control
lever
in

N

posi

tion
2
If

engine
speed
cannot
be

adjust

ed

properly
with

adjusting
screw

check
and

adjust
clearance
e

again

3

Depress
and
release
accelerator

pedal
several
times
and
make

sure
that

engine

speed
reduces
to
800

rpm
as

pedal
is

released

If
correct

adjustment
is
not
made

repeat

steps
I
to
3
above
until

engine
speed
is

800

rpm
at

idling

1

FlCD

adjusting
screw

2
Lever
A

3
Lever
B

4

Cable
lo
k

screw
Clearance

e

AC381
A

Fig
AC
24
Fast
Idle
Actuotor

AC
18
REMOVAL
AND

INSTALLATION

Remove

vacuum
hose
from
actua

tor

2

Remove
air

cleaner

assembly

3

Remove
cotter

pin
and

pin
and

disconnect

actuator
from
F

LC
D

lever
connected

to
throttle
shaft

4

Remove

actuator

attaching
nuts

then
remove
actuator

5
Install

actuator
in

the
reverse

order
of
removal

6
After

installing
adjust
actuator

Refer
to

Adjustment
of

Idle

Speed

REFRIGERANT
LINES
Air

Conditioning

@

I

J

L

S

r
Z
S
t

@

See

Fig
AC
29
When

replacing

flexible
hose
and
tube
observe
the

following

1

Before

starting
work
be

sure
to

discharge
system

2

When

disconnecting
tubes
be

sure
to

use
two

wrenches
on
both

tubes

3

After
discon

ecting
tubes

plug

all

openings
immediately
to

prevent

entrance
of
dirt
and
moisture

4

Compressed
air
must
never
be

used
to
clean

dirty
line
Clean
with

refrigerant

gas

5
In

connecting
tubes
be
sure
to

apply
compressor
oil
to

seating
surface

and
then

tighten
tubes
to

specified

tightening
torque
See

Fig
AC
30

Be

sure
to
use
two
wrenches
when

tightening
a
flare

nut
of
tube

Coat
seat
surfaces
with
com

pressor
oil
and
then

tighten

AC263

Fig
AC

30
Line
Connection
CD

6
Make
sure

refrigerant
line
is

clamped
securely
Start

engine
and

raise

engine
speed
to

inspect
if
there
is

vibration
or
unusual
noise

7

Conduct
leak
t
st
and
make
su
e

that
there
is
no
leak

from
connections

8
Refer
to

General
Service
for

evacuating
and

charging
system

COOLING
UNIT

REMOVAL

I

Disconnect

battery
ground
cable

2

Discharge

refrigerant
from

sys

tern
Refer
to
General
Service

3
Loosen

flare
nuts
at
each
con

nection
of
inlet

and
outlet

pipes
of

evaporator

AC
21
1

High
pressure
discharge
service

valve

2
Low

pressure
suction
service
valve

3

Compressor

4

Condenser

5
Receiver

drier

6

Cooling
unit

7

Low

pressure
switch

lightening
torque

kg
m
ft
lb

@
4

5
to

5
0
33
to
36

@
3
0
to
3
5
22
to
25

AC385A

Fig
AC
29

Refrigerant
Lines

CAUTION

Immediatelv
plug
up
all

openings

to

prevent
entrance
of

dirt
and

moisture

4
Remove
instrument
under

cover

5
Remove

glove
box

6
Disconnect

wiring
harness

con

nectors
from

compressor
relay
and

thermostat

7
Remove

upper
and
lower

attach

ing
bolts
and

remove

cooling
unit

AC386A

Fig
AC
31
Removing
Cooling
Unit

Air

Conditioning

BLOWER
MOTOR
DIAGNOSES

I
Blower
motor
inoperative

I
Check
20

ampere
fuse
in
air
conditioner
harness

Fuse
blown
Fuse

OK

Locate
short
circuited

spot
and

repair

or

replace
faulty

parts
Ground
one
of
lead
wires

Black
blue
3

speed
Black
white
2

speed

Black

yellow
l

speed
1eading
to
fan

switch

Blower
runs
Blower
does

not
run

Check

ground
circuit
and

lead
wire
con

oeetion
When
no

problem
is
found

replace
blower

switch
Ground
black
wire

of
blower
motor

i

Blower

runs
Blower
does
not

run

Check
resistor
for
connection
When

no

problem
is
found

replace
resistor
Connect
12
volt

test

light
to
white
wire

leading
to

blower
motor

Light
ON
Light
OFF

Check
lead
wire
for
connection

When

no

problem
is
found

replace
blower
motor
Check
for

presence
of

voltage
at
main

relay

No
Yes

Check
for

presence
of

voltage
at
air

conditioner
harness
Check

lead
wire
for
connection

When
no

problem
is
found

replace
relay

AC
33

Air

Conditioning

COMPRESSOR
CLUTCH
DIAGNOSES

Compressor
clutch
is

not

engaged

Check
20

arnpere
fuse
in
air
conditioner

harness

Fuse
blown

Fuse
OK

Locate
short

circuited

spot
and

repair
or

replace
damaged
parts
Connect
12
volt
test

light
to

compressor

clutch
lead
wire
Ground
the
other
end
of

test

light
Set
air
control
lever

to
A
C

posi

tion

Light
ON
Light
OFF

I

Check
low

pressure
switch
for

continuity

L
H
drive

only
Check
lead

wire
and

ground
wire
of

compres

sor
clutch
for
connection
When
there
is

nothing
wrong
with
them

replace

compressor

clutch

No

I
Yes

Measure

pressure
in

system
If
there
is
a

leak
service

system
If

pressure
is
normal

check
low

pressure
switch
as
a

part
reo

place
if

necessary
Connect
12
volt
test

light
to
terminal
of

blue

green
wire

leading
to
thermostat

Ground
the
other

end
of
test

light

Light
ON
Light
OFF

Check

ground
circuit
and
make

sure
of

proper
connection

Further

check
lead
wire
connection

and
when

no

problem
is

found

replace
air
conditioner

harness
or
main

harness
Connect
12

volt
test

light
to
blue
white
wire

of
microswitch
Ground
the
other
end
of

test

light

I

Light
ON

I
Light
OFF

I

Check
lead
wire
connection

When
no

problem
is
found

replace
thermostat
Check
for
current
flow
in

lead
wire
to
main

relay

Yes

I
I
No

Check
lead
wire

for
connection

When
no

problem
is

found

replace

microswitch
or
main

relay
Check

power

supply

AC
35

v

Air

Conditioning

VACUUM
SYSTEM
DIAGNOSES

FAST
IDLE
CONTROL

DEVICE

F
I
C
O
does
not

operate

Disconnect

vacuum
hose
from
fast
idle
actuator
and
connect

vacuum
tester

light
ON

Light
OFF

Replace
actuator

Disconnect

magnet
valve
hose
at
intake
mani

fold
side

and
connect
vacuum
tester
to
the

open
end

of
the
hose
and

magnet
valve

light
ON

I
light
OFF

Connect
12
volt
test

light
between

magnet

valve
lead
wires
Check
vacuum
connector
and

hose
If
hose

or

connectors
are

damaged

replace
it

light
ON

light
OFF

Replace
magnet
valve
Inspect
circuit
of

magnet
valve

Refer
to

Compressor
Clutch

Diagnoses

Note

Vacuum
lester
Tester

Iighl
keeps
OFF
unless
normal
wcuum
level
exists

in
each
check

point

AC
36

PERFORMANCE
TEST

DIAGNOSES

Of
various
conditions
caused
to
the

air

conditioning
system
the

character

istics
revealed
on
manifold

gauge
read

ing
are
shown

in
the

following

Condition
Air

Conditioning

As

to
the
method

of
a

perfonnance

test
refer
to
the
item

of
Perfonnance

Test

Note
In
the

following
table
the

portion
smeared
with
ink

on
each

I
INSUFFICIENT
REFRIGERANT

CHARGE

I

I

@
@

08A

I
ALMOST
NO

REFRIGERANT

i

@

@

AC209A

I
FAULTY
EXPANSION
VALVE

I

I

@
@

AC210A
Insufficient

cooling

Bubbles

appear
in

sight

glass
Probable
cause

Refrigerant
is
small

or

leaking
a
little

No

cooling
action
Serious

refrigerant
leak

In

sight
glass
appear
a

lot

of
bubbles
or

something

like
mist

Slight
cooling

Sweating
or
frosted

expan

sion

valve
inlet

AC37
Expansion
valve
restricts

refrigerant
flow

Expansion
valve
is

clog

ged

Expansion
valve
is
in

operative

Valve
stuck

closed

Thermal
bulb

has

lost

charge
gauge
scale
indicates
a

range
based

on
the

assumption
that
the
air

conditioning
system
is
in

good

order

Corrective
action

I

Leak
test

2

Repair
leak

3

Charge
system

Note
Evacuate

8S
neces

sary
and

recharge

sys

tem

Stop
rompressor
immedi

ately

I

Leak

test

2

Discharge
system

3

Repair
leak
s

4

Replace
receiver
drier

if

necessary

5

Check
oilleve

6
Evacuate
and

recharge

system

If
valve
inlet
reveals
sweat

or
frost

I

Discharge
system

2
Remove

valve
and

clean

it

Replace
it

if
neces

sary

3

Evacuate

system

4

Charge
system

If
valve
does

not

operate

I

Discharge
system

2

Replace
valve

3
Evacuate
and

charge

system