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Fig. 4: Adjusting A/C Compressor Belt
Courtesy of MAZDA MOTORS CORP.
POWER STEERING PUMP
Loosen power steering pump bolt and nuts and adjust belt deflection by turning adjusting bolt. See Fig. 3
, Fig.
6 and Fig. 7 . See ADJUSTMENT SPECIFICATIONS . Tighten bolts to specification. See TORQUE
SPECIFICATIONS .
DRIVE BELT ROUTING
1991 Mazda MX-5 Miata
1990-93 ENGINE COOLING Drive Belt Routing & Adjustment - MX-5 Miata
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Fig. 5: Identifying Drive Belt Routing & Deflection Check Point (1 Of 3)
Courtesy of MAZDA MOTORS CORP.
1991 Mazda MX-5 Miata
1990-93 ENGINE COOLING Drive Belt Routing & Adjustment - MX-5 Miata
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Page 290 of 392
Fig. 6: Identifying Drive Belt Routing & Deflection Check Point (2 Of 3)
Courtesy of MAZDA MOTORS CORP.
1991 Mazda MX-5 Miata
1990-93 ENGINE COOLING Drive Belt Routing & Adjustment - MX-5 Miata
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Fig. 7: Identifying Drive Belt Routing & Deflection Check Point (3 Of 3)
Courtesy of MAZDA MOTORS CORP.
ADJUSTMENT SPECIFICATIONS
DEFLECTION SPECIFICATIONS
NOTE: Check belt deflection when engine is cold, or has bin off for 30 minutes.
Application(1) Specification - In. (mm)
New Belt (2)
Alternator0.31-0.35 (8-9)
A/C Compressor0.31-0.35 (8-9)
Power Steering Pump0.31-0.35 (8-9)
Used Belt
Alternator0.35-0.39 (9-10)
A/C Compressor0.35-0.39 (9-10)
Power Steering Pump0.35-0.39 (9-10)
(1)Deflection with 22 lbs. (10 kg) pressure applied midway on belt run.
Used on for less than 5 minutes.
1991 Mazda MX-5 Miata
1990-93 ENGINE COOLING Drive Belt Routing & Adjustment - MX-5 Miata
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TENSION SPECIFICATIONS
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS
(2)
Application(1) Specification - Lbs. (kg)
New Belt (2)
Alternator110-132 (50-60)
A/C Compressor110-132 (50-60)
Power Steering Pump110-132 (50-60)
Used Belt
Alternator95-110 (43-50)
A/C Compressor95-110 (43-50)
Power Steering Pump95-110 (43-50)
(1)Measure tension using Tension Gauge (49 9200 020), or equivalent.
(2)Used on for less than 5 minutes.
ApplicationFt. Lbs. (N.m)
Alternator Adjusting Bolt
"A"14-18 (19-25)
"B"27-38 (37-52)
A/C Compressor Locknut27-38 (37-52)
Power Steering Pump Adjusting Bolt
"A"23-44 (31-46)
"B"27-40 (37-54)
"C"14-18 (19-25)
1991 Mazda MX-5 Miata
1990-93 ENGINE COOLING Drive Belt Routing & Adjustment - MX-5 Miata
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Page 295 of 392

SWITCHES
SWITCHES LOCATION
MISCELLANEOUS
MISCELLANEOUS LOCATION
COMPONENT LOCATION GRAPHICS
ComponentLocation
Idle Speed Control SolenoidOn throttle body.
Purge Control Solenoid ValveOn right side of engine compartment, on shock
tower.
ComponentLocation
A/C Pressure SwitchOn high pressure refrigerant line.
Back-Up Light SwitchOn left side of transmission.
Clutch SwitchOn bracket, above clutch pedal. See Fig. 2 .
Neutral SwitchOn right rear side of transmission. See Fig. 2 .
Parking Brake SwitchOn base of parking brake lever.
Power Steering Pressure SwitchOn power steering housing assembly. See Fig. 2 .
Seat Belt Buckle SwitchOn driver's side seat belt buckle.
Stoplight SwitchOn bracket, above brake pedal. See Fig. 2 .
ComponentLocation
Diagnostic Check ConnectorOn left rear of engine compartment, near master cylinder. See Fig. 2 .
IgniterOn right rear corner of engine compartment, near fuse/relay block. See
Fig. 2
.
SRS Back-Up BatteryMounted below SRS control unit. See Fig. 3 .
NOTE: Figures may show multiple component locations. Refer to appropriate table for
proper figure references.
1991 Mazda MX-5 Miata
ELECTRICAL COMPONENT LOCATOR 1991 MAZDA ELECTRICAL COMPONENTS
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A/C-HEATER SYSTEM - MANUAL
1990-92 Manual A/C-Heater Systems
A/C SYSTEM SPECIFICATIONS
A/C SYSTEM SPECIFICATIONS
DESCRIPTION
Blower case, mounted under right end of instrument panel, contains blower motor and fresh/recirculated air
door. Evaporator case, to left of blower case, contains evaporator, evaporator thermoswitch and expansion
valve. Heater case, to left of evaporator case, contains airflow mode door and air-mix (temperature blend) door.
ELECTRICAL COMPONENT LOCATIONS
OPERATION
All air control doors are controlled manually by cable from control panel. Top lever controls the air-mix door,
center lever controls the fresh/recirculated air door and bottom lever controls the airflow mode door.
ApplicationSpecification
Compressor TypeNippondenso Rotary Vane
Compressor Belt Deflection (1) (2)
New5/16-23/64" (8-9 mm)
Used23/64-25/64" (9-10 mm)
Compressor Oil Capacity2.7-3.3 oz.
Refrigerant (R-12) Capacity28 oz.
System Operating Pressures
High Side171-235 psi (12.0-16.5
kg/cm
2 )
Low Side21-43 psi (1.5-3.0 kg/cm2 )
(1)With 22 lbs. (10 kg) pressure applied to center of belt.
(2)On vehicles with P/S, measure midway between crankshaft pulley and P/S pump pulley. On vehicles
without P/S, measure midway between crankshaft pulley and A/C idler pulley.
ComponentLocation
A/C RelayIn Right Front Corner Of Engine Compartment
Blower Motor RelayIn Left Rear Corner Of Engine Compartment
Blower ResistorOn Bottom Of Blower Case
Evaporator Thermoswitch. On Left Side Of Evaporator Case
Pressure SwitchIn High-Pressure Line, Between Receiver-Drier
And Evaporator
1991 Mazda MX-5 Miata
A/C-HEATER SYSTEM - MANUAL 1990-92 Manual A/C-Heater Systems
1991 Mazda MX-5 Miata
A/C-HEATER SYSTEM - MANUAL 1990-92 Manual A/C-Heater Systems
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Disconnect electrical connectors from blower case. Remove glove box. Loosen seal plate between blower motor
case and evaporator case. Remove blower motor case nuts. Remove case and seal plate. To install, reverse
removal procedure.
COMPRESSOR
Removal & Installation
1. Disconnect negative battery cable. Discharge A/C system using approved refrigerant recovery/recycling
equipment. Disconnect compressor clutch connector. Disconnect refrigerant lines from compressor.
Remove drive belt.
2. Raise and support vehicle. Remove compressor mounting bolts and remove compressor. To install,
reverse removal procedure. Adjust drive belt to specified tension. Evacuate and charge system.
CONDENSER & RECEIVER-DRIER
Removal & Installation
Discharge A/C system using approved refrigerant recovery/recycling equipment. Raise and support vehicle.
Remove splash shield and air guide. Remove condenser and receiver-drier as an assembly. To install, reverse
removal procedure. Evacuate and charge system.
CONTROL PANEL
Removal & Installation
Remove rear console assembly. See Fig. 4 . Remove vent outlets from center panel assembly. Remove center
panel assembly. Remove control panel screws. Pull control panel from hole. Disconnect door control cables
from back of control panel and remove panel. To install, reverse removal procedure.
EVAPORATOR CORE & THERMOSWITCH
Removal & Installation
1. Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove condenser and
receiver-drier as an assembly. Disconnect low-pressure and high-pressure pipes from evaporator tubes at
engine compartment firewall.
2. Remove right undercover and glove box. Disconnect thermoswitch electrical connector. Loosen left seal
plate (between heater case and evaporator case). Loosen right seal plate (between evaporator case and
blower motor case).
3. Remove evaporator case. Disassemble evaporator case, and remove evaporator core and thermoswitch.
See Fig. 3
. To install, reverse removal procedure. Evacuate and charge system.
1991 Mazda MX-5 Miata
A/C-HEATER SYSTEM - MANUAL 1990-92 Manual A/C-Heater Systems
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