ACURA NSX 1997 Service Repair Manual

Heater Core Temperature Sensor

Removal

Disconnect the connector, remove the clamp and the

heater core temperature sensor.

CLAMP

HEATER CORE

TEMPERATURE

SENSOR
Compare the resistance reading between the terminals

of the heater core temperature sensor with specifica-

tions shown in the following graph: It should be within

specification.

NOTE: Dip the sensor in ice water, and measure the

resistance. Then pour hot water on the sensor, and

check for change in resistance.
Test

CAUTION: The sensor uses a thermistor which

can be damaged if high current is applied to it

during testing. Therefore, use a circuit tester

that puts out a measuring current of 1 mA or

less.ProCarManuals.com

Evaporator Temperature Sensor
Removal
Give th e evaporato r temperatur e senso r a quarte r turn ,
then pul l ou t t o remov e it .
EVAPORATO RTEMPERATUR E SENSO R
Test
Compar e th e resistanc e readin g betwee n th e terminal s
of th e evaporato r temperatur e senso r wit h specificatio n
shown i n th e followin g graph : I t shoul d b e withi n
specification .
NOTE : Di p th e senso r i n ic e water , an d measur e th e
resistance . The n pou r ho t wate r o n th e sensor , an d
chec k fo r chang e i n resistance .
CAUTION : Th e senso r use s a thermisto r whic h
ca n b e damage d if hig h curren t i s applie d t o it
durin g testing . Therefore , us e a circui t teste r
tha t put s ou t a measurin g curren t o f 1 m A o r
less .
ProCarManuals.com

Aspirator Fa n
Tes t
Connec t batter y powe r t o th e No . 3 termina l o f th e
aspirato r fan , an d connec t groun d t o th e No . 4 terminal .
Th e aspirato r fa n shoul d run .
Rela y
Test
Ther e shoul d b e continuit y betwee n th e C an d D
terminals .
Ther e shoul d b e continuit y betwee n th e A an d B termi -
nal s whe n powe r an d groun d ar e connecte d t o th e C
an d D terminals .
Ther e shoul d b e n o continuit y whe n powe r i s discon -
nected .
• Compresso r clutc h rela y
• Blowe r moto r rela y
• Blowe r moto r hig h rela y
Condense r fa n rela y
ProCarManuals.com

Blower Uni t
Replacemen t
1. Remov e th e spar e tir e (refe r t o Owner' s manual) .
2. Remov e th e spar e tir e holder .
CORROSIO N RESISTAN T BOL T
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
SPARE TIR E
HOLDE R
3. Disconnec t th e cable s fro m th e battery , loose n th e
hold-dow n bracke t nuts , an d remov e th e hold -
dow n bracket . Then , remov e th e battery .
BATTER Y
HOLD-DOW NBRACKET
4. Remov e th e under-hoo d rela y bo x A an d th e wate r
drai n duct . Disconnec t th e connector s fro m th e
blowe r motor , powe r transisto r an d recirculatio n
contro l motor .
CORROSIO N RESISTAN T BOL T
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
WATE RDRAINDUCT
BLOWE R MOTOR ,
POWE R TRANSISTOR ,
an d RECIRCULATIO N CONTRO L
MOTOR CONNECTOR S 6 x 1. 0 m m
9. 8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
5. Remov e th e mountin g bolts , the n remov e th e blowe r
unit.
CORROSIO N RESISTAN T BOL T
BLOWE RUNIT
6 x 1. 0 m m9.8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
6. Instal l th e blowe r uni t i n th e revers e orde r o f
removal , the n mak e sur e i t run s an d doesn' t lea k
any air .
UNDER-HOO DRELAYBOX A
ProCarManuals.com

Blower Unit

Overhaul

RECIRCULATION

CONTROL MOTOR
BLOWER MOTOR

POWER

TRANSISTORProCarManuals.com

A/C Servic e Tip s an d Precaution s
The ai r conditionin g syste m use s HFC-134 a (R-134a ) refrigeran t and polyalkyleneglyco l (PAG ) refrigeran t oil*, whic h are
not compatibl e wit h CFC-1 2 (R-12 ) refrigeran t an d minera l oil . D o no t us e R-1 2 refrigeran t o r minera l oi l i n thi s system , an d
d o no t attemp t t o us e R-1 2 servicin g equipment ; damag e t o th e ai r conditionin g syste m o r you r servicin g equipmen t wil l result .
*DENS O ND-OIL8 :
• P/N 3889 9 - PR 7 - A01 : 4 0 ( 1 1/ 3 fl-oz , 1. 4 Imp-oz )
• P/ N 38897-PR7-A01AH : 12 0 ( 4 fl-oz , 4. 2 Imp-oz )
Onl y us e servic e equipmen t tha t i s U.L.-liste d an d i s certifie d t o mee t th e requirement s o f SA E J221 0 t o remov e R-134 a
from th e ai r conditione r system .
CAUTION : Exposur e t o ai r conditione r refrigeran t an d lubrican t vapo r o r mis t ca n irritat e eyes , nos e an d throat , Avoi d
breathin g th e ai r conditione r refrigeran t an d lubrican t vapo r o r mist .
I f accidenta l syste m discharg e occurs , ventilat e wor k are a befor e resumin g service .
R-134 a servic e equipmen t o r vehicl e ai r conditione r system s shoul d no t b e pressur e teste d o r lea k teste d wit h compresse d air .
Som e mixture s o f ai r an d R-134 a hav e bee n show n t o b e combustibl e elevate d pressure s an d ca n resul t
i n fir e o r explosio n causin g injur y o r propert y damage . Neve r us e compresse d ai r t o pressur e tes t R-134 a servic e
equipmen t o r vehicl e ai r conditionin g systems .
Additional healt h an d safet y informatio n ma y b e obtaine d fro m th e refrigeran t an d lubrican t manufacturers .
1. Alway s disconnec t th e negativ e cabl e fro m th e batter y wheneve r replacin g ai r conditionin g parts .
2 . Kee p moistur e an d dus t ou t o f th e system . Whe n disconnectin g an y lines , plu g o r ca p th e fitting s immediately ; don' t
remov e th e cap s o r plug s unti l jus t befor e yo u reconnec t eac h line .
3 . Befor e connectin g an y hos e o r line , appl y a fe w drop s o f refrigeran t oi l t o th e O-ring .
4. Whe n tightenin g o r loosenin g a fitting , us e a secon d wrenc h to suppor t th e matchin g fitting .
5. Whe n recoverin g th e system , us e a R-134 a refrigeran t Recovery/Recycling/Chargin g System ; don' t releas e
refrigeran t int o th e atmosphere .
6 . Ad d refrigeran t oi l afte r replacin g th e followin g parts :
NOTE :
• D o no t retur n th e oi l t o th e containe r onc e dispense d an d neve r mi x wit h othe r refrigeran t oil s t o avoi d
contamination .
• Immediatel y afte r usin g th e oil , replac e th e ca p o n th e containe r an d sea l i t t o avoi d moistur e absorption .
• D o no t spil l th e refrigeran t oi l o n th e vehicle ; i t ma y damag e th e paint ; i f th e refrigeran t oi l contact s th e paint , was h
i t of f immediately .
Condense r
............... . 1 0 (1/ 3 fl-oz, 0.4 Imp-oz )
Evaporato r .............. . 1 0 (1/ 3 fl-oz , 0. 4 Imp-oz )
Lin e o r hos e ............ . 2 0 (2/ 3 fl-oz , 0. 7 Imp-oz )
Receive r ................... . 1 0 (1/ 3 fl-oz , 0. 4 Imp-oz )
Compresso r ............ . O n compresso r
replacement , subtrac t th e volum e o f oi l draine d
from th e remove d compresso r fro m 16 0 ( 5 1/ 3
fl-oz , 5. 6 Imp-oz) , an d drai n th e calculate d volum e
of oi l fro m th e ne w compressor : 16 0 ( 5 1/ 3
fl-oz , 5. 6 Imp-oz ) — Volum e o f oi l fro m remove d
compresso r = Volum e t o drai n fro m ne w compres -
sor.
CORROSIO N RESISTAN T BOL T
Suctio n hos e an d discharg e hos e
t o A/ C line s ................................. . 2 2 N- m (2. 2 kgf-m , 1 6 Ibf-ft )
Discharg e lin e C
(bot h sides ) .................................. 23 N- m (2. 3 kgf-m , 1 7 Ibf-ft )
Condense r lin e A
(bot h sides ) ................................. . 2 3 N- m (2. 3 kgf-m , 1 7 Ibf-ft )
Condense r lin e C to lef t sid e
condense r .................................... . 1 4 N- m (1. 4 kgf-m , 1 0 Ibf-ft )
Receiver/drye r ............................ . 1 4 N- m (1. 4 kgf-m , 1 0 Ibf-ft ) Receive
r lin e an d suctio n lin e t o heate r
assembl y ..................................... . 2 2 N- m (2. 2 kgf-m , 1 6 Ibf-ft )
Compresso r hos e mountin g
bolt s ............................................. . 2 2 N- m (2. 2 kgf-m , 1 6 Ibf-ft )
Compresso r mountin g
bolt s ............................................. . 2 2 N- m (2. 2 kgf-m , 1 6 Ibf-ft )
Compresso r bracke t
mountin g bolt s ........................... . 4 4 N- m (4. 5 kgf-m , 3 3 Ibf-ft )
Idle r pulle y cente r nu t ................ . 4 4 N- m (4. 5 kgf-m , 3 3 Ibf-ft )
6 m m bol t ................................ . 9. 8 N- m (1. 0 kgf-m , 7. 2 Ibf-ft )
ProCarManuals.com

A/C System Service

Performance Test

The performance test will help determine if the air con-

ditioning system is operating within specifications.

Only use service equipment that is U.L.-listed and is cer-

tified to meet the requirements of SAE J2210 to remove

HFC-134a (R-134a) from the air conditioning system.

CAUTION: Exposure to air conditioner refrigerant

and lubricant vapor or mist can irritate eyes, nose

and throat. Avoid breathing the air conditioner

refrigerant and lubricant vapor or mist.

If accidental system discharge occurs, ventilate work

area before resuming service.

R-134a service equipment or vehicle air conditioning sys-

tem should not be pressure tested or leak tested with

compressed air.

Some mixtures of air and R-134a have

been shown to be combustible at elevated pressures

and can result in fire or explosion causing injury or

property damage. Never use compressed air to pres-

sure test R-134a service equipment or vehicle air

conditioning systems.

Additional health and safety information may be obtained

from the refrigerant and lubricant manufacturers.

1. Connect a R-134a refrigerant Recovery/Recycl-

ing/Charging System to the vehicle as shown fol-

lowing the equipment manufacturer's instructions.

2. Insert a thermometer in the center vent outlet.

Determine the relative humidity and air

temperature by calling the local weather informa-

tion line.

3. Test conditions:

• Avoid direct sunlight.

• Open engine cover.

• Open the doors.

• Set the temperature control dial to MAX COOL

and push the mode control button to VENT and

FRESH button.

• Turn the fan switch to MAX.

• Run the engine at 1,500 RPM.

• No driver or passengers in vehicle.

4. After running the air conditioning for 10 minutes

under the above test conditions, read the delivery

temperature from the thermometer in the dash vent

and the high and low system pressure from the A/C

gauges.
Recovery/Recycling/Charging SystemProCarManuals.com

5. To complete the charts:

• Mark the delivery temperature along the vertical

line.

• Mark the intake temperature (air temperature)

along the bottom line.

• Draw a line straight up from the air temperature

to the humidity.

• Mark a point one line above and one line below

the humidity level. (10% above and 10% below

the humidity level)

• From each point, draw a horizontal line across to

the delivery temperature.

• The delivery temperature should fall between the

two lines.

• Complete the low side pressure test and high side

pressure test in the same way.

INTAKE TEMPERATURE

INTAKE TEMPERATUREProCarManuals.com

A/C Syste m Servic e
Pressur e Tes t Char t
NOTE : Performanc e Tes t o n pag e 22-70 .
see pag e 22-8 9see pag e 22-9 1
ProCarManuals.com

Recovery
Only us e servic e equipmen t tha t i s U.L.-liste d an d i s cer -
tified t o mee t th e requirement s o f SA E J221 0 to remov e
HFC-134 a (R-134a ) fro m th e ai r conditionin g system .
CAUTION : Exposur e t o ai r conditione r refrigeran t
an d lubrican t vapo r o r mis t ca n irritat e eyes , nos e
an d throat . Avoi d breathin g th e ai r conditione r
refrigeran t an d lubrican t vapo r o r mist .
I f accidenta l syste m discharg e occurs , ventilat e wor k
are a befor e resumin g service .
R-134a servic e equipmen t o r vehicl e ai r conditionin g sys -
tem shoul d no t b e pressur e teste d o r lea k teste d wit h
compresse d air .
Som e mixture s o f ai r an d R-134 a hav e
bee n show n t o b e combustibl e a t elevate d pressure s
an d ca n resul t i n fir e o r explosio n causin g injur y o r
propert y damage . Neve r us e compresse d ai r t o pres -
sur e tes t R-134 a servic e equipmen t o r vehicl e ai r
conditionin g systems .
Additiona l healt h an d safet y informatio n ma y b e obtaine d
fro m th e refrigeran t an d lubrican t manufactures .
1 . Connec t a R-134 a refrigeran t Recovery/Recycl -
ing/Chargin g Syste m t o th e vehicl e a s show n fol -
lowin g th e equipmen t manufacturer' s instructions .
2. Measur e th e amoun t o f refrigeran t oi l remove d
fro m th e A/ C syste m afte r th e recover y proces s i s
completed .
NOTE: B e sur e t o instal l th e sam e amoun t o f ne w
refrigeran t oi l bac k int o th e A/ C syste m befor e
charging .
Recovery/Recycling/Chargin g System .
ProCarManuals.com