A double-lock mechanism is used on clockspring connectors. DO NOT use excessive force when
disconnecting connectors, as damage to connector may occur.
DISABLING & ACTIVATING AIR BAG SYSTEM
AIR BAG SYSTEM
DISABLING SYSTEM
On Miata, obtain radio code number from customer, and deactivate audio anti-theft function. On all models,
turn ignition switch off. Disconnect and shield negative battery cable. Remove knee protector. Disconnect
Orange and Blue clockspring connectors at base of steering column. See Fig. 1
.
ACTIVATING SYSTEM
Reconnect battery and clockspring connectors. Turn ignition switch to RUN position. Check AIR BAG
indicator li
ght to ensure system is operating properly. See SYSTEM OPERATION CHECK. WARNING:Wait about 10 MINUTES after disabling air bag system before servicing.
Air bag system voltage is maintained for about 10 MINUTES after system
is disabled. Failure to wait 10 MINUTES before servicing system may
cause accidental air bag deployment and possible personal injury.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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ADJUSTMENTS
CLOCKSPRING CENTERING
Set front wheels in straight-ahead position. Turn clockspring connector clockwise until it stops (do not force).
Return connector 2 3/4 turns counterclockwise. Rotate clockspring connector further, if necessary, to align
marks on connector and outer housing.
DISPOSAL PROCEDURES
DEPLOYED AIR BAG
Dispose deployed air bag module as you would any other part. Wear gloves and safety glasses when handling
air bag module.
SCRAPPED VEHICLE
1. Ensure vehicle is outside, and away from other vehicles and people. Open convertible top and doors.
Disconnect negative battery cable.
2. Ensure air bag module is firmly mounted to steering wheel. Remove knee protector and disconnect
Orange and Blue clockspring connectors at base of steering column. See Fig. 1
. Cut clockspring
connector Blue wires.
3. Connect 2 jumper wires (20 feet long) to cut clockspring wires. Connect other ends of wires to a 12-volt
battery to deploy air bag. Because of heat, wait 10 MINUTES before touching deployed air bag.
REMOVAL & INSTALLATION
CRASH SENSORS NOTE: Perform the following procedures when scrapping a vehicle with undeployed air
bag.
WARNING:Follow air bag service precautions to prevent accidentalair bag
deployment and personal injury. See SERVICE PRECAUTIONS.
NOTE: After component replacement, check system to ensure proper operation. See
SYSTEM OPERATION CHECK.
NOTE: Crash sensor orientation and mounting is important for proper operation. All
sensors must be positioned so that arrow points forward. If there is sheet metal
damage near sensor mounting point, inspect body structure at sensor
mounting point for deformation. If damaged, restore to original shape. Ensure
sensor mounting bolts or nuts are tightened to specification. See TORQUE
SPECIFICATIONS table.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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Fig. 13: Identifying Rear Safing Sensor Terminals
Courtesy of MAZDA MOTORS CORP.
DIAGNOSTIC TEST NO. 6
Warning Light Flashes 6 Times
1. Disconnect negative battery cable. Check connection of Orange/Blue clockspring connector; repair as
necessary.
2. If connection is okay, disconnect air bag module and clockspring connector. Check continuity, as shown
in illustration, for both terminals of Blue side of clockspring connector. See Fig. 14
. If continuity is not
present, replace Oran
ge/Blue clockspring connector.
1991 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM MAZDA 1990-91 AIR BAGS
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ABS DIODE
Continuity Test
1. Unplug hydraulic unit 12-pin connector. On Miata, connect positive lead of DVOM to Blue/Yellow wire
terminal and negative lead to Gray wire terminal of hydraulic unit. On RX7, connect positive lead of
DVOM to Red wire terminal and negative lead to Yellow/Red wire terminal of hydraulic unit.
2. On 929, connect positive lead of DVOM to Violet wire terminal and negative lead to Yellow/Red wire
terminal of hydraulic unit. Ensure continuity is present between terminals. Reverse DVOM leads.
Continuity should not be present with leads reversed. If ABS diode does not test as described, replace
ABS diode.
ABS SYSTEM GROUND
Continuity Test (Miata)
Using a DVOM, check for continuity between terminals "D", "S", and "f" of control unit harness connector and
ground. See Fig. 4
or Fig. 5 . If continuity is not present, repair harness.
Continuity Test (RX7 & 929)
Use DVOM to check continuity. ON RX7, check between control unit harness connector terminal "D" and JC-
02 connector. See Fig. 4
and Fig. 6 or Fig. 5 and Fig. 7 . On 929, check between control unit harness connector
terminal "T" and JC-02 connector. If continuity is not present, repair harness.
1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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Fig. 3: Interior Fuse Panel Identification
Courtesy of MAZDA MOTOR OF AMERICA, INC.
Fuse & Circuit Breaker Identification
11 - 15 Amp (Blue) Engine Cooling Fan
12 - 10 Amp (Red) Gauges, Warning Lights, Turn Signal Lights, Cruise Control
13 - 15 Amp (Blue) Air Bag
14 - 30 Amp Heater
15 - Empty
16 - 30 Amp (Green) Power Windows
17 - 20 Amp (Yellow) Wipers, Washers
18 - Empty
19 - 15 Amp (Blue) Taillights
20 - Empty
21 - 15 Amp (Blue) Shift Lock, Cruise Control, Horn, Stoplights
22 - 15 Amp (Blue) Hazard Warning Lights
1991 Mazda MX-5 Miata
FUSES & CIRCUIT BREAKERS Fuses & Circuit Breakers 1990-95 Mazda
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23 - Empty
24 - 10 Amp (Red) Interior Lights, Warning Buzzers, Radio/Cassette, Compact Disc Player, Clock
25 - 15 Amp (Blue) Radio/Cassette, Compact Disc Player, Clock, Cigarette Lighter
26 - Empty
27 - Empty
BATTERY SPECIFICATIONS
Vehicle is equipped with a special 9 9/16" x 4 3/4" x 7 3/8" 12-volt battery that is vented to outside of vehicle.
CAUTIONS & WARNINGS
SUPPLEMENTAL RESTRAINT SYSTEM (AIR BAG)
Modifications or improper maintenance, including incorrect removal and installation of the Supplemental
Restraint System (SRS), can adversely affect system performance. DO NOT cover, obstruct or change the
steering wheel horn pad in any way, as such action could cause improper function of the system. Use only plain
water when cleaning the horn pad. Solvents or cleaners could adversely affect the air bag cover and cause
improper deployment of the system.
AIR CONDITIONING SERVICING CAUTION: When battery is disconnected, vehicles equipped with computers may
lose memory data. When battery power is restored, driveability problems
may exist on some vehicles. These vehicles may require a relearn
procedure. See COMPUTER RELEARN PROCEDURES article in the
GENERAL INFORMATION Section.
NOTE: See the AIR BAGS article in the ACCESSORIES/SAFETY EQUIPMENT Section.
WARNING:To avoid injury from accidental air bag deployment, read and carefully
follow all warnings and service precautions. See appropriate AIR BAGS
article in ACCESSORIES/SAFETY EQUIPMENT.
CAUTION: Disconnect negative battery cable before servicing any air bag system,
steering column or passenger side dash component. After any repair, turn
ignition key to the ON position from passenger's side of vehicle in case of
accidental air bag inflation
CAUTION: Avoid breathing R-134a refrigerant and PAG lubricant vapors, exposure
may irritate eyes, nose and throat. To remove R-134a from system use R-
134a recycling equipment that meets SAE J2210 specifications. If
accidental system discharge occurs, ventilate work area before resuming
1991 Mazda MX-5 Miata
FUSES & CIRCUIT BREAKERS Fuses & Circuit Breakers 1990-95 Mazda
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ADJUSTMENTS
AIRFLOW MODE DOOR
Set airflow mode control lever to vent position. Disconnect control cable at airflow mode door lever. Extend
airflow mode door lever until it stops, and hold it there. See Fig. 1
. Attach control cable to door lever and clip.
Ensure control lever moves freely between defrost and vent positions.
AIR-MIX (TEMPERATURE BLEND) DOOR
Set temperature control lever to maximum hot position. Disconnect control cable at air-mix door lever. See Fig.
1 . Extend air-mix door lever until it stops, and hold it there. Attach control cable to door lever and clip. Ensure
control lever moves freely between hot and cold positions.
RECIRCULATED/FRESH AIR DOOR
Set recirculated/fresh air control lever to fresh position. Disconnect control cable at recirculated/fresh air door
lever. Retract recirculated/fresh air door lever until it stops, and hold it there. Attach control cable to door lever
and clip. Ensure control lever moves freely between recirculated air and fresh air positions.
TESTING
BLOWER MOTOR CIRCUIT
1. Check 30-amp HEATER circuit breaker in passenger compartment fuse panel. If Red button has not
popped out, go to next step. If Red button has popped out, repair short circuit and press Red button to
reset circuit breaker.
2. Turn ignition on. Turn blower switch to 4th position (high). Check voltage at Blue wire terminal of 2-
wire blower motor connector on bottom of blower case. If no voltage is present, repair wiring between
circuit breaker and blower motor.
3. If battery voltage is present, turn off blower switch and A/C switch (if equipped). Check voltage at
Blue/Red wire terminal of blower resistor 1-wire connector. If no voltage is present, replace blower
motor. If battery voltage is present, check voltage at Blue/White wire terminal of blower resistor
connector.
4. If no volta
ge is present, replace blower resistor. If battery voltage is present, check voltage at Blue/Red WARNING:To avoid injury from accidental air bag deployment, read and carefully
follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR
BAG SYSTEM procedures in AIR BAG article in the
ACCESSORIES/SAFETY EQUIPMENT Section.
NOTE: Blower resistor uses a 1-wire connector and a 4-wire connector. The wire
in the 1-wire connector is Blue/Red, and one of the wires in the 4-wire
connector is Blue/Red. Check voltage at appropriate wire.
1991 Mazda MX-5 Miata
HEATER SYSTEM 1990-92 Heater Systems
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wire terminal of blower resistor 4-wire connector. If no voltage is present, replace blower resistor.
5. If battery voltage is present, check voltage at Blue/Green wire terminal of blower resistor connector. If no
voltage is present, replace blower resistor. If battery voltage is present, check voltage at Blue/Yellow wire
terminal of blower resistor connector.
6. If no voltage is present, replace blower resistor. If battery voltage is present, turn ignition on and blower
switch to 4th position (high). Check voltage at Black wire terminal of blower switch connector. If battery
voltage is present, repair wiring between blower switch and ground.
7. If no voltage is present, turn ignition switch, blower switch and A/C switch off. Check voltage at
Blue/White wire terminal of blower switch connector. If no voltage is present, repair wiring between
blower resistor and blower switch.
8. If battery voltage is present, check voltage at Blue/Red wire terminal of blower switch connector. If no
voltage is present, repair wiring between blower resistor and blower switch. If battery voltage is present,
check voltage at Blue/Green wire terminal of blower switch connector.
9. If no voltage is present, repair wiring between blower resistor and blower switch. If battery voltage is
present, check voltage at Blue/Yellow wire terminal of blower switch connector. If battery voltage is
present, replace blower switch. If no voltage is present, repair wiring between blower resistor and blower
switch.
BLOWER MOTOR
Disconnect 2-wire connector from bottom of blower motor case. Apply battery voltage across terminals.
Replace blower motor if it does not operate.
BLOWER SWITCH
With blower switch in positions indicated, check continuity between specified terminals of blower switch
connector. See Fig. 2
. If continuity is not as specified, replace blower switch.
1991 Mazda MX-5 Miata
HEATER SYSTEM 1990-92 Heater Systems
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