charging ACURA NSX 1991 Service Repair Manual

Alternator (ALT ) F R Signa l
This signal s th e EC M whe n th e Alternato r (ALT ) i s charging .
Inspection o f AL T F R Signal .
ECM CONNECTOR S
WIR E SID E O F FEMAL E TERMINAL S
Chec k fo r a shor t i n th e wire :
1. Tur n th e ignitio n switc h OFF .2. Disconnec t th e negativ e bat -
ter y cabl e fro m th e battery .
3 . Disconnec t th e EC M connec -
tor D (22P ) fro m th e ECM .4. Chec k fo r continuit y betwee n
EC M connecto r termina l D 5
an d bod y ground .
I
s ther e approx . 5 V ?
Chec
k fo r a shor t i n th e circuit :
1 . Disconnec t th e GR N 4 P con -
necto r fro m th e ALT .
2. Tur n th e ignitio n switc h O N (II) .3. Measur e voltag e betwee n EC M
connecto r terminal s D 5 an d
A26 .
Is ther e continuity ? Repai
r shor t i n th e wir e betwee nthe EC M (D5 ) and th e ALT .
Substitut e a known-goo d EC M
an d recheck . I f prescribe d voltag e
i s no w available , replac e th e origi -
nal ECM .Chec k th e operatio n o f th e ALT :1. Tur n th e ignitio n switc h OFF .2. Reconnec t th e AL T GR N 4 P
connecto r t o th e ALT .
3 . Star t th e engine . Hol d th e
engin e a t 3,00 0 rp m wit h n oloa d (A/ T in position ,M/T in neutral ) unti l th e radiato r
fa n come s on , the n le t i t idle .
4 . Measur e voltag e betwee n EC M
connecto r terminal s D 5 an d
A26.
Doe s th e voltag e decreas e whe nhead light s an d rea r defogge r ar eturne d on ? AL
T F R signa l i s OK .
(T o pag e 11-120 )
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Recovery

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 manufactures.

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

ing/Charging System to the car as shown following

the equipment manufacturer's instructions.

2. Measure the amount of refrigerant oil removed

from the A/C system after the recovery process is

completed.

NOTE: Be sure to install the same amount of new

refrigerant oil back into the A/C system before

charging.
Recovery/Recycling/Charging System.ProCarManuals.com

Heater-Evaporator Unit

Replacement

SRS components are located in this area. Review the SRS
component locations, precautions, and procedures in the
SRS section (24) before performing repairs or service.
1.
Remove
the
blower
unit
(see
page
22-67 ('93-'96),
63('91-'92)).

2. When the engine is cool, drain the engine coolant from the radiator (see section 10).
Do not remove the radiator cap when

the engine is hot; the engine coolant is under

pressure and could severely scald you.

CAUTION: Engine coolant will damage paint. Quick-

ly rinse any spilled engine coolant off painted sur-

faces.
3. Disconnect the heater valve cable from the heater valve.

4.
Disconnect
the
heater hoses. Engine cootant
will
run out when the hoses are disconnected, drain it
into a clean drip pan.

HEATER

VALVE CASLE
HEATER VALVE
5. Recover the refrigerant from the A/C system with a
R-134a refrigerant Recovery/Recycling/Charging
System. (see page 22-73).
6. Disconnect the receiver line and the suction line from the evaporator. Cap the open fittings immediately
to keep moisture out of the system.

RECEIVER LINE

New parts (R-134a)

SECTION LINE

7. Remove the dashboard (see section 20).
8. Remove the heater duct. 9. Remove the four mounting bolts, disconnect the con-
nectors from the control units and the evaporator

temperature sensor connector from the control unit

bracket, then remove the control unit bracket.
*: CORROSION RESISTANT BOLT
EVAPORATOR

TEMPERATURE
SENSOR CONNECTOR
CONTROL

UNIT

BRACKET
SRS MAIN

HARNESS

* 6 x 1,0 mm
10 N·m
(1.0 kg-m,
7 Ib-ft)

* 6 x 1.0 mm
10 N·m (1.0 kg-m, 7 Ib-ft)
10. Remove the woofer enclosure (see section 23).ProCarManuals.com

Replacement
1. Disconnect the negative cable from the battery.
2. Remove the from bumper (see section 20).
3. Recover the refrigerant using a R-134a refrigerant Recover/Recycling/Charging System (see page

22-73).

4. Disconnect the discharge line C and the condenser lines from the condenser. Cap the open fittings

immediately to keep moisture and dirt out of the

system.

(Right Condenser)

CONDENSER
LINE A
DISCHARGE
LINE C

(Left Condenser)

CONDENSER
LINE C
CONDENSER
LINE A
5. Disconnect the connector from the condenser fan,
remove the two mounting bolts and nut, then
remove the condenser.

*: CORROSION RESISTANT BOLT

(Right Condenser)

NUT

CONNECTOR
RIGHT CONDENSER

* MOUNTING BOLTS
6 x 1,0 mm
10 N·m (1.0 kg-m, 7 Ib-ft)

(Left Condenser)
CONNECTOR
NUT

LEFT CONDENSER * MOUNTING BOLTS
6 x 1.0 mm
10 N·m (1.0 kg-m. 7 Ib-ft)
6. Install the condenser in the reverse order of removal; and:
If you're installing a new condenser, add
refrigerant oil (ND-OIL 8) (see page 22-69 ).
Replace 0-rings with new ones at each fitting,
and apply refrigerant oil to them.
NOTE: Be sure to use the right O-rings for
R-134a to avoid leakage. Charge the system (see page 22-91) and test its
performance (see page 22-70).
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A/C System Service

Evacuation

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. When an A/C System has been opened to the at-

mosphere, such as during installation or repair, it

must be evacuated using a R-134a refrigerant

Recovery/Recycling/Charging System. (If the

system has been open for several days, the

receiver/dryer should be replaced).

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

ing/Charging System to the car as shown follow

the equipment manufacturer's instructions.

NOTE: If low pressure does not reach more than

700 mm Hg (27 in-Hg) in 1 5 minutes, there is pro-

bably a leak in the system. Partially charge the

system and check for leaks (see Leak Test).
Recovery/Recycling/Charging SystemProCarManuals.com

A/C Syste m Servic e
Leak Tes t
Only us e servic e equipmen t tha t i s U.L.-liste d an d is cer -
tified to 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-134 a servic e equipmen t o r vehicl e ai r conditionin g sys -
te m 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 to 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
conditione r 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 manufacturers .
1 . Connec t a R-134 a refrigeran t Recovery/Recycl -
ing/Charging Syste m to th e ca r a s show n followin g
the equipmen t manufacturer' s instructions .
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 .
2 . Ope n hig h pressur e valv e t o charg e th e syste m to
abou t 10 0 kP a (1. 0 kg/cm2, 1 4 psi) , the n clos e th e
suppl y valve .
3 . Chec k th e syste m fo r leak s usin g a R-134 a
refrigeran t lea k detecto r wit h a n accurac y o f
0.5/oz . pe r yea r o r better .
4 . I f yo u fin d leak s tha t requir e th e syste m to b e open -
e d (t o repai r o r replac e houses , fittings , etc.) ,
recove r th e syste m accordin g t o th e Recove r Pro -
cedur e o n pag e 22-73 ).
5 . Afte r checkin g an d repairin g leaks , th e syste m
mus t b e evacuate d (se e Syste m Evacuatio n o n
pag e 22-89 ).
Recovery/Recycling/Chargin g Syste m
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Charging
Only 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 HFC-134 a (R-134a ) fro m 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 . Additiona l healt h an d safe -
t y informatio n ma y b e obtaine d fro m th e refrigeran t an d
lubrican t manufacturers .
Refrigeran t capacity : 800-85 0 g (28-3 0 oz )
CAUTION : D o no t overcharg e th e system ; th e
compresso r wil l b e damaged .
Connec t a R-134 a refrigeran t Recovery/Recycl -
ing/Chargin g Syste m to th e ca r a s show n follo w th e
equipmen t manufacturer' s instructions .
Recovery/Recycling/Chargin g Syste m
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Battery

Test

• Battery fluid (electrolyte) contains sulfuric acid. It may cause severe burns if it gets on your skin or in your eyes.

Wear protective clothing and a face shield.

— If electrolyte gets on your skin or clothes, rinse it off with water immediately.

— If electrolyte gets in your eyes, flush it out by splashing water in your eyes for at least 15 minutes; call a physician

immediately.

• A battery gives off hydrogen gas. If ignited, the hydrogen will explode and could crack the battery case and splatter

acid on you. Keep sparks, flames, and cigarettes away from the battery.

• Overcharging will raise the temperature of the electrolyte. This may force electrolyte to spray out of the battery vents.

Follow the charger manufacturer's instructions and charge the battery at a proper rate.

Use either a JCI or Bear ARBST tester, and follow the manufacturer's procedures. If you don't have one of these com-

puterized testers, follow this conventional test procedure:

To get accurate results, the temperature of the electrolyte must be between 70°F (21 °C) and 100°F (38°C).

Check For Damage

If the case is cracked or the posts are loose,

replace the battery.

Check Indicator EYE Color

If the indicator shows low electrolyte, add

distilled water if possible.

EYE Indicates OK
EYE Indicates LOW

CHARGE

Test Load Capacity (#1)

Apply 300 amp load for 15 seconds to remove

surface charge.

Allow 15 seconds recovery period.

Apply test load (see Test Load Chart).

Record voltage at the end of 15 seconds.

Stays above 9.6 volts;

battery is OK.
Drops below 9.6 volts.ProCarManuals.com

Charging Syste m
Componen t Locatio n Inde x
CHARGIN G SYSTE M LIGH T(Built int o th e gaug e assembly )Test, pag e 23-10 0
BATTER YTest, pag e 23-6 8
ALTERNATO R BEL TAdjustment , pag e 23-10 9
ALTERNATO R• Alternato r an d Regulato r Test , pag e 23-10 2
• Replacement , pag e 23-10 5
• Overhaul , pag e 23-10 6
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Charging Syste m
Troubleshootin g
If th e chargin g syste m ligh t i s on , o r th e batter y i s dea d o r low , tes t th e followin g item s i n th e orde r listed :
1. Batter y (se e pag e 23-68 )
2. Chargin g Syste m Ligh t
3. Alternator/Regulato r
Charging Syste m Ligh t Tes t
Does th e chargin g syste m ligh tcom e on ?
Star t th e engine .
Doe s th e chargin g syste m ligh t
go off ?
Turn th e ignitio n switc h off .
Disconnec t th e 4- P connecto r
fro m th e alternator .
Tur n th e ignitio n switc h O N (II) .
WHT/BL U wir e i s OK ; perfor m
alternator/regulato r tes t (se e pag e
23-102 ).
Doe s th e chargin g syste m ligh t
com e on ? (T
o pag e 23-101 )
Chargin g syste m ligh t circui t i s
OK .
Disconnec t th e AB S contro l uni t
(C237) , EP S contro l uni t (C251) ,
an d th e integrate d contro l uni t
(C401) , a s applicable . I f th e
chargin g syste m ligh t stay s on ,
repai r th e shor t t o groun d i n th eWHT/BL U wire .
Tur
n th e ignitio n switc h O N (II) .
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