1995 NISSAN ALMERA N15 Service Manual

PRECAUTIONSANDPREPARATION
HFC-134a (R-134a)ServiceToolsandEquipment
(Cont'd)

Tool name
Electrical leakdetector
Manifold gaugeset(with
hoses andcouplers)
Service hoses
• High sidehose
• Low side hose
• Utility hose
Service couplers
• High sidecoupler
• Low side coupler
Refrigerant weightscale
Vacuum pump
(Including theisolator
valve) Description

NT19S
NT199
NT201
NT202
NT200
NT203 HA-7
Note
Power supply:
• DC 12V(Cigarette lighter)
Identification:
• The gauge faceindicates R-134a.
Filling size:Thread size
• 1/2"-16 ACME
Hose color:
• Low hose: Bluewithblack stripe
• High hose: Redwith black stripe
• Utility hose:Yellow withblack stripe or
green withblack stripe
Hose filting togauge:
• 1/2"-16 ACME
Hose filling to
service
hose:
• M14 x1.5 fitting isoptional or
permanently attached.
For measuring ofrefrigerant
Fitting size:Thread size
.1/2"-16 ACME
Capacity:
• Air displacement: 4CFM
• Micron rating:20microns
• Oil capacity: 482g(17 oz)
Fitting size:Thread size
.1/2"-16 ACME
•

PRECAUTIONSANDPREPARATION
Precautions forService Equipment
RECOVERY/RECYCLING/RECHARGING EQUIPMENT

Be certain tofollow themanufacturers instructionsformachine
operation andmachine maintenance. Neverintroduce any
refrigerant otherthanthatspecified intothemachine.

ELECTRONIC LEAKDETECTOR

Be certain tofollow themanufactures instructionsfortester
operation andtester maintenance.

With isolator valve
Without isolatorvalve
VACUUM
PUMP

Hose fittings:

1/2".16ACME
Thelubricant contained insidethevacuum pumpisnot compat-
ible with thespecified lubricantforHFC-134a (R-134a)
AIC
sys-
tems. Thevent sideofthe vacuum pumpisexposed toatmo-
spheric pressure. Sothe vacuum pumplubricant maymigrate
out ofthe pump intotheservice hose.Thisispossible whenthe
pump isswitched offafter evacuation (vacuuming) andhose is
connected toit.
To prevent thismigration, useamanual valveplaced nearthe
hose-to-pump connection,asfollows.
• Usually vacuum pumpshaveamanual isolatorvalveaspart
of the pump. Closethisvalve toisolate theservice hose
from thepump.
• For pumps without anisolator, useahose equipped witha
manual shut-off valvenearthepump end.Close thevalve
to isolate thehose fromthepump.
• Ifthe hose hasanautomatic shutoffvalve, disconnect the
hose fromthepump. Aslong asthe hose isconnected, the
valve isopen andlubricating oilmay migrate.
Some one-way valvesopenwhen vacuum isapplied andclose
under ano vacuum condition. Suchvalves mayrestrict the
pump's abilitytopull adeep vacuum andarenotrecom-

RHA270D
mended.

MANIFOLD GAUGESET

Be certain thatthegauge faceindicates R-134aor134a. Besure
the gauge sethas
1/2"-16
ACMEthreaded connections forser-
vice hoses. Confirm theset has been usedonlywith refriger-
ant HFC-134a (R-134a)andspecified lubricants.

~

1f2"-16ACME

SHA533D

Hose fittings to
manifold gaugeorrecovery/recycling
equipment; 1/2"-16ACME

RHA272DSERVICE
HOSES

Be certain thattheservice hosesdisplay themarkings
described (coloredhosewithblack stripe). Allhoses must
include positive shutoffdevices (eithermanual orautomatic)
near theend ofthe hoses opposite themanifold gauge.

HA-8

Open

Close

AIC

service valve
Counterclockwise
Clockwise
Shut
offvalve rotation

Never
attempt toconnect HFC-134a (R-134a)servicecouplers to
an CFC-12 (R-12)
A/C
system. TheHFC-134a (R-134a)couplers
will notproperly connecttothe CFC-12 (R-12)system. However,
if an improper connection isattempted, discharging andcon-
tamination mayoccur.

REFRIGERANT WEIGHTSCALE

Verify thatnorefrigerant otherthanHFC-134a (R-134a)and
specified lubricants havebeenusedwiththescale. Ifthe scale
controls refrigerant flowelectronically, thehose fitting mustbe

1/2"-16 ACME.
RHA274D
PRECAUTIONS
ANDPREPARATION
Precautions forService Equipment (Cont'd)
SERVICE COUPLERS
RHA273D
M14

x
1.5 fitting
optional (Hose maybe
permanently
attached to
coupler)

Hose fittings:

1/2"-16ACME
To manifold gauge
CHARGING CYLINDER

Using acharging cylinderisnot recommended. Refrigerant
may bevented intoairfrom cylinder's topvalve whenfilling the
cylinder withrefrigerant. Also,theaccuracy ofthe cylinder is
generally lessthan thatofan electronic scaleorofquality
recycle/recharge equipment.

•

HA-9

DESCRIPTION
Refrigeration Cycle
REFRIGERANT FLOW

The refrigerant flowisinthe standard pattern.Refrigerant flowsthrough thecompressor, condenser,
liquid tank,evaporator andback tothe compressor.
The refrigerant evaporation throughtheevaporator coiliscontrolled byan externally equalizedexpan-
sion valve, located insidetheevaporator case.

FREEZE PROTECTION

The compressor cyclesonand offtomaintain theevaporator temperature withinaspecified range.When
the evaporator coiltemperature fallsbelow aspecified point,thethermo controlamplifier interrupts the
compressor operation.Whentheevaporator coiltemperature risesabove thespecification, thethermo
control amplifier allowscompressor operation.

REFRIGERANT SYSTEMPROTECTION
Dual-pressure switch

The dual-pressure switchislocated onthe liquid tank.Ifthe system pressure risesorfalls outof
specifications, theswitch openstointerrupt compressor clutchoperation.

Fusible plug

Open attemperature above105°C(221°F), thereby discharging refrigeranttothe atmosphere. Ifthis plug
is melted andopened, checktherefrigerant lineand replace liquidtank.

c:::::.J
High-pressure
EJ
Low-pressure
gas liquid

1:-:-:-:-::-:-::-:-:1
~~~~pressure
!::i'i'i':}':J
~~:-pressure
Compressor

D

Outside air

U
s

t

Fusible plug-~
~..
U

'" Expansionvalve
Liquid tank"'--Dual-pressure switch

HA-10
Blower
motor

SHA504D

270-271-272-273

SEC.

tnozzle
Side defros er

__________
~==D=ES=C~R~I~P~TI~O~N~~---------

Component Layout

Defroster nozzle
Sidedefroster nozzle
.1 tor duct
Side venlia Center
ventilator duct
Control assembly Side
ventilator duct
Cooling unit

•

D models. ositetothis layout.
.
.11 stration isfor
LH .
symmetrically opp
This
I
u RHOmodels
IS

The layout for

RHA312F
HA-11

DESCRIPTION
Discharge AirFlow
@ Todefroster
Floor
Defroster
.... ;Air passed through heatercore

<$=::I :
Mixed air(...
+
<;::::J )

<:;:::::J ;
Air not passed through heatercore
This
illustration isfor LHD models.
The layout forRHD models issymmetrically opposite.
Ventilator
door

CD;

Ventilation
@:
Defroster
@; Fool
Bi-Ievel
(~ switch"OFF")
RHA313F
HA-12

DESCRIPTION
Control Operation
LHO models RHO
models
FAN CONTROL KNOB

This knob turns thefan ONand OFF, andcontrols fanspeed.

MODE CONTROL KNOB

This knob controls theoutlet airflow.

TEMPERATURE CONTROLKNOB

This knob allows adjustment ofthe temperature ofthe outlet air.

RECIRCULATION (REC)SWITCH

OFF position:
Outside airisdrawn intothepassenger compartment.
ON position:
Interior airisrecirculated insidethevehicle.
The indicator lampwillalso light.

AIR CONDITIONER SWITCH

The airconditioner switchcontrols the
Ale
system. Whentheswitch isdepressed withthefan ON, the
compressor willturn ON.The indicator lampwillalso light.

The airconditioner coolingfunction operates onlywhen theengine isrunning.
HA-13
•

TROUBLEDIAGNOSES
Contents
How toPerform TroubleDiagnoses forQuick andAccurate Repair HA-15
Operational Check HA-16
Symptom Chart HA-18
Preliminary Check HA-20
PRELIMINARY CHECK1

(A/C
does notblow coldair.) HA-20
PRELIMINARY CHECK2
(Air outlet doesnotchange.) HA-21
PRELIMINARY CHECK3
(Noise) HA-22
PRELIMINARY CHECK4
(I nsufficient heating) HA-23
Performance TestDiagnoses HA-24
INSUFFICIENT COOLING HA-24
Performance Chart HA-26
TEST CONDITION HA-26
TEST READING HA-26
Trouble Diagnoses forAbnormal Pressure HA-27
Harness Layout. HA-31
Circuit Diagram -Air Conditioner HA-34
Wiring Diagram -HEATER - HA-36
Wiring Diagram -AIC - HA-38
Main Power Supply andGround CircuitCheck HA-49
Diagnostic Procedure1
(SYMPTOM: Blowermotordoesnotrotate.) HA-50
Diagnostic Procedure2
(SYMPTOM: Intake doordoes notchange.) HA-52
Diagnostic Procedure3
(SYMPTOM: Magnetclutchdoesnotoperate when
A/C
switch andfanswitch areON.)
- For GAand SRengines HA-54
- For CDengine HA-59
Electrical Components Inspection HA-62
Control Linkage Adjustment HA-64
System Description HA-65
HA-14