bulb DATSUN PICK-UP 1977 User Guide

Body
Electrical

System

METERS
AND

GAUGES

COMBINATION
METER

COMBINATION
METER
CIRCUIT

DIAGRAM

REMOVAL
AND

INSTALLATION

SPEEDOMETER

REMOVAL
AND

INSTALLATION

ODOMETER
SWITCH

REMOVAL
AND

INSTALLATION

FUEL
GAUGE
AND

WATER
TEMPERATURE

GAUGE

DESCRIPTION

REMOVAL
AND

INSTALLATION

OIL

PRESSURE
WARNING
LAMP

DESCRIPTION

01
L

PRESSURE
SWITCH

COMBINATION

METER

COMBINATION
METER

CIRCUIT
DIAGRAM

@

BE6828
CONTENTS

BE
14

BE
14

BE
16

BE
16

BE
16

BE
16

8E
16

BE
16

BE
16

BE
16

8E
17

BE
17

BE
17

Turn

signal

indicator

lamp

L
H

OIL

0

BEAM

BE
14
Meter
illumination

lamps

M
T

only

9

9
Turn

sq
nal

indicator

lamp

lL
J
R
H

Tj

O
iJ

I
l

g
r
i
o

I

l8

J
CHARGE

WARNING
LAMP

DESCRIPTION

HAND

BRAKE
WARNING
LAMP

DESCRIPTION

HAND
BRAKE

SWITCH

METER

ILLUMINATION

INDICATOR

AND

WARNING
BULBS

REMOVAL
AND

INSTALLATION

8ULB

SPECIFICATIONS

TROUBLE

DIAGNOSES
AND

CORRECTIONS

SPEEDOMETER

WATER
TEMPERATURE

AND
FUEL

GAUGES

OIL

PRESSURE
AND

CHARGE
WARNING

LAMPS

Voltage

regulator

TEMP

FUEL
CHG

0

BRK

C

I

Speedometer

2
Thermometer

3
Fuel
meter

4
Tachometer

Option

5

Cluster
lid

6

Speedometer
cable

7

Speed
switch

amplifier

Manual
transmission

only
BE
17

BE
17

BE
18

BE
18

8E
18

8E
18

BE
18

BE
18

BE
18

BE
18

BE
19

BE
20

Q
Speed

switch

BE856A

Fig
BE

21
Ci1
Cuit

diagram
of
combination

meter

HAND
BRAKE

WARNING
LAMP

DESCRIPTION

The
hand

brake

warning
lamp
glows

when
the
hand
brake
is

applied

When
the

ignition
switch
is

set
to

ON
current
flows
from
the

ignition

switch

to
the

warning
lamp
When
the

hand
brake
is

applied
hand
brake

warning
switch
is
closed
and

warning

lamp
glows

Fuse

M

Ignition
5
tch

Fusible
link

From

battery
I

YG

1
1

Hand
brake
sWitch

BE314

Fig
BE
28

Circuit

of
hand
broke

warning

Iystem
Body
Electrical

System

HAND
BRAKE

SWITCH

To

remove
hand
brake

switch
dis

connect

lead
wire

pull
switch

out
of

hand
brake

control
bracket

and
with

draw
switch

and

wiring

assembly
METER

ILLUMINATION

INDICATOR
AND

WARNING

BULBS

REMOVAL
AND

INSTALLATION

To

replace
bulb
turn

bulb
socket

counterclockwise
to
dismount
it

from

combination
meter
if

necessary
dis

connect
lead
wire

connector
from

printed
circuit

and
remove
bulb
from

socket

BULB

SPECIFICATIONS

Item

Meter
illumination

lamp

Turn

signal
indicator

lamp

High
beam

indicator

lamp

Oil

pressure
warning

lamp

Charge
warning

lamp

Hand
brake

warning

lamp

Clock

illumination

lamp
SAE
Trade

Bulb
No
Wattage

Candle

power

W

e

161

161

161

161

161

158

158
1
7

I
x3

1
7

I

1
7
I

I
7
I

1
7

I

3
4
2

3
4
2

TROUB

E
DIAGNOSES
AND

CORRECTIONS

SPEEDOMETER

Condition

Speedometer
pointer

and

odometer
do
not

operate

Unstable

speedometer

pointer

Unusual
sound

occurs

in

response
to

in

crease
in

driving
speed
Probable
cause

Loose

speedometer
cable
union
nut

Broken

speedometer
cable

Damaged
speedometer
drive

pinion
gear

Transmission
side

Inoperative

speedometer

Improperly
tightened
or
loose

speedometer

cable

union
nut

Faulty
speedometer
cable

Inoperative
speedometer

ExceS

jvelybent
or
twisted

speedOmeter

cable
inner

wire

or
lack

of
lubrication

Inoperative
speedometer

8El8
Coirective
action

Retighten

Replace

Replace

Replace

Retighten

Replace

Replace

Replace
or
lubricate

Replace

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

Body
Electrical

System

ELECTRICAL
ACCESSORIES

CONTENTS

HORN

DESCRIPTION

REMOVAL
AND
INSTALLATION

IGNITION
SWITCH

REMOVAL
AND
INSTALLATION

INSPECTION

WINDSHIELD
WIPER
AND
WASHER

REMOVAL
AND
INSTALLATION

INSPECTION

RADIO

REMOVAL
AND
INSTALLATION

ADJUSTMENT

CLOCK

REMOVAL

I
NST
ALLA
TION

HEATER

DESCRIPTION

AIRFLOW

HEATER
UNIT
ASSEMBLY
BE
21

BE
21

BE
21

8E
n

BE
22

BE
22

BE
23

BE
23

BE
23

BE
25

BE
25

BE
25

BE
25

BE
25

BE
26

BE
26

BE
26

BE
28

BE
29

HORN

DESCRIPTION

The

horn
circuit
includes

a
horn

relay
Current
from
the

battery
flows

through
the
fusible
link
and
fuse
to

the
horn

relay
terminal
B

where
it
is

shunted

by
the
two
circuits
In
one

circuit
terminal
S
the
current
flow
is

supplied
through
the
solenoid
and

Fusible
link

Qi
att
Fu

H

I
HIBQ

t
J

JJI

L
J

Hornrelay

Qm
HEATER
CORE

FAN

MOTOR

CONTROL
ASSEMBLY

ADJUSTMENT

SPECIFICATIONS

TACHOMETER

REPLACEMENT

8UL8
REPLACEMENT

SEAT
8ELT
WARNING

SYSTEM

DESCRIPTION

REMOVAL
AND
INSTALLATION

WARNING
LAMP
BULB
REPLACEMENT

INSPECTION

TROUBLE
DIAGNOSES
AND

CORRECTIONS

HORN

WINDSHIELD
WIPER
AND
WASHER

RADIO

Horn
button

BE859A

Fig
BE

29
Circuit

diagram
of
horn

sy
tem
horn
button

to
the

ground
In

the

other
circuit
terminal
H
the
current

flow
is

supplied
through
the

relay

contacts
and
horn

Horn
bracket

serves
as
a

grounding

When
the
horn
button
is

pressed

current
from
the

battery
energizes
the

solenoid
As
the
solenoid
is

energized

the

relay
contacts
are
closed
This

allows
the
current
to
flow
to
the
horn

BE
21
REMOVAL
AND

INSTALLATION

Horn
8E
29

BE
29

BE
29

8E
29

BE
30

BE
30

BE
30

8E
30

8E
31

BE
31

BE
31

8E
31

8E
31

BE
33

8E
33

8E

34

BE
35

I

Disconnect

battery
ground
cable

2
Disconnect
horn
wire
at
terminal

on
horn

body

3
Remove
horn

retaining
bolt

4
Install
horn
in
the
reverse
se

quence
of
removal

Horn

relay

The
horn

relay
is
installed
on
the

hoodIedge
on
the

right
side
of
the

engine
compartment

I
Disconnect

battery
ground
cable

2
Disconnect
horn
relay
wire
con

nector
at
terminals
on
horn
relay

3
Remove

retaining
screws

4
Install
horn

relay
in
the
reverse

sequence
of
removal

TEMP
lever

1

Move
TEMP
lever
to
the

OFF

position

2
Connect
control
cable
to
the
lever

of
water
ock
when

water
cock
lever
is

pulled
forward

fully
closed

3
Install
control
cable
on
water

cock
bracket
with
cable

retaining
clip

SPECIFICATIONS

Item

FAN
MOTOR

Rated

power
consumption

Revolution

rpm

Fan
dia
mm
in

TACHOMETER

The
tachometer
is

optional
on

model
HL620
It
is
an

integral
part
of

the

ignition
system
It
counts
the

pulses
entering
the

ignition
coil
and

indicates
the

number
of

engine
revolu

tions

REPLACEMENT

I

Remove

battery
ground
cable

2

Remve
cluster
lid

following

instructions
iri

steps
I
to
4
of
Removal

in

Combination
Meter
Body
Electrical

System

BE872A

Fig
BE

52
Water
cock

General
use
Extremely
cold

weather

use
2
RG
The
red

with

green

stripe
lead

wire

must
be

connected
to

flat

plate
terminal
at
back
of

combination
meter

3
B

The
black
lead

wire
must
be

connected

to
T

shaped
ter

minal
at
back
of

combination

meter

4

YR

The

yellow
with

red

stripe

lead
wire
must

be
connected

to

pole
terminal
at
back
of

combination
meter

6
Pass

tachllmeter
wires

through

grommet
on
hood
lock
control
wire

and
connect
to

negative
terminal
of

ignition
coil

Notes

a

Fix

grommet
with
an
adhesive

tape

or
a

sealing
compound
to

prevent

water

leakage

b
Attach
tachometer
wires
to
hood

lock

control
wire
with
an
adhesive

tape

BULB
REPLACEMENT

I
Remove
tachometer
as

previously

described

2

Twist
illumination
bulh
socket
at

back
of
tachometer
Bulb
with
socket

can
then
be

easily
removed

3

Remove
bulb

4

Install
new
bulb
in

reverse
se

quence
of
removal

Bulb

wattage

Tachometer
illumination

lamp
3
4W
12V

less
than
36W

3

600

110
433
12V

less
than
SSW

2

SOO

110
4
33

3
Disconnect

four
tachometer
lead

wire
connectors

They
are
connected

to

combination
meter
and
tachometer

cable

4

Remove
three

screws
and
then

remove
tachometer
from

cluster
lid

5

Install
in
reverse

sequence
of
re

moval
When

connecting
lead
wire

note

the

following

1
BW
The
black
with
white

striped

lead
wire

must
be
connected

to

identically
colored
ta

chometer

cable

coming
from

engine

compartment

BE

30
BE965

Fig
BE
53

Tachometer

SEAT
BELT

WARNING
SYSTEM

DESCRIPTION

Except
Canada

When

the

ignition
switch
is
turned

to
the
ON

position
the

warning

lamp
comes
on

and
remains
on
for
4

to
8

seconds
The

warning
buzzer

sounds
for
4

to
8
seconds
intermittent

ly
if
the
driver
s
seat
belt
is

not

fastened

properly

The
seat
belt

warning
system
con

sists
of
a
driver
s
belt
switch
a

warning

buzzer
a

warning
lamp
a
timer
unit

and
an

ignition
switch

For
Canada

When
the

ignition
switch
is
turned
Body
Electrical

System

to
the

ON

position
the

warning

lamp
comes
on
and
the

warning
buz

zer
sounds
if
the
driver

s
seat
belt
is

not

fastened

properly

The
seat
belt

warning
system
con

sists
of

a
driver
s

belt
switch

a

warning

buzzer

a

warning
lamp
and
an

igni

tion
switch

REMOVAL
AND

INSTALLATION

Ignition
switch

Refer
to

page
BE
22

for
Removal

and
Installation

Timer
unit

Timer
unit
is
fIXed

on
a
reinforce

ment
behind

glove
box

BE688B

I
Disconnect

battery
ground
cable

2
Remove

glove
box

3
Disconnect
timer
unit

connector

4
Remove
two
screws

retaining

timer
unit
on
reinforcement
Timer

unit
can
then
be
taken

out

S

Installation
is
in
the
reverse
se

quence
of
removal

Warning
buzzer

Warning
buzzer
is
fIxed

on
a
re

inforcement
behind

glove
box

Refer
to
the

preceding
timer
unit

for
Removal
and
Installation
BE282B

Fig
BE
54
Timer
unit

BE967A

Fig
BE
55
Warning
buzzer

Driver
s
seat
belt
switch

I
Remove
seat
belt

ecuring
bolt

2
Disconnect
belt
switch
lead
wire

at
connector

3

Seat
belt
can
then
be
taken
out

4

Installation
is
in
the

reverse
se

quence
ofremoval

BE
31
Warning
lamp
body

Warning

lamp
is

located
on
instru

ment

panel

I
Remove

cluster
lid

2
Disconnect

lead
wire

at
connee

tor

3
Remove

two
screws

retaining

lamp
body

4

Installation
is
in
the

reverse
se

quence
of
removal

WARNING
LAMP
BULB

REPLACEMENT

I
Remove
cluster

lid

2
Twist

warning
lamp
socket

Socket
with
bulb

can
then
be
taken

out

3

Pick

up
bulb

from
socket

4
Install
new
bulb
in
the
reverse

sequence
of
removal

Bulb

wattage

Seat
belt

warning
lamp
I
7W

INSPECTION

Warning
buzzer

Apply
12V

direct
current
between

CD
and

@
and
check
whether
buzzer

sounds
or
not

The
buzzer

must
sound
when

CD

and

@
are
connected
to

power

circuit
See

Figure
BE
55
for

warning

buzzer

Note
Make

sure
that

negative

terminal
of

power
circuit
is

always

connected

to

@
terminal

Timer
unit

Turn

ignition
key
to
the

ON

position
The

voltage
between

@
and

ground
must
be
12V
for
4

to
8

seconds
and
then

go
out
See

Figures

BE
54
and
BE
56

Belt
switch

Test

continuity
between
two
lead

wires
from
seat
belt
switch
with
ohm

meter
or
test

lamp

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

Body
Electrical

System

TROUBLE
SHOOTING
GUIDE

Condition

Warning
lamp
does
not

light
in
START

posi

tion

of

ignition
switch
Probable
cause

Burnt
or

loose
bulb

Faulty
f1o
r

temperature
relay

Loose
connection

or

open
circuit

BE
44
Corrective
action

Replace
bulb

or
correct
bulb
socket

Conduct

continuity
test
and

repair
or
reo

place

Refer
to
Section

EC

Check

wiring
and
or

repair
if

necessary

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

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