1991 MAZDA MIATA head

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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Battery voltage is always applied to terminal "B".
DO NOT ground terminal "L" while engine is running.
DO NOT start engine with connector disconnected from terminals "L" and "S".
DO NOT apply battery voltage to terminal "L".
ON-VEHICLE TESTING
ALTERNATOR OUTPUT
1. Connect an ammeter (80-amp minimum) in-line between terminal "B" connector and wire. See Fig. 2
,
Fig. 3
and Fig. 4 . Turn all headlights and accessories on and depress brake pedal. With engine operating
at 2500-3000 RPM, measure output amperage. NOTE: Check alternator wiring harness connections and drive belt tension. Battery
must be fully charged before testing. Wait at least 30 seconds after starting
engine before measuring system voltage.
CAUTION: Ensure alternator terminal "B" does not contact ground.

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
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ELECTRICAL COMPONENT LOCATOR
1991 MAZDA ELECTRICAL COMPONENTS
BUZZERS, RELAYS & TIMERS
BUZZERS, RELAYS & TIMERS LOCATION
CIRCUIT PROTECTION DEVICES
CIRCUIT PROTECTION DEVICES LOCATION
CONTROL UNITS
ComponentLocation
ABS System
Check Valve RelayOn top of ABS pump motor.
Motor RelayOn top of ABS pump motor.
Buzzer & Timer UnitOn bracket, behind left side of dash.
See Fig. 1
.
Circuit Opening RelayOn bracket, behind left side of dash.
See Fig. 1
.
Cooling Fan RelayIn engine compartment fuse/relay
block. See Fig. 1
.
Dashboard Illumination Lights RelayOn bracket, near master cylinder. See
Fig. 1
.
EFI Main RelayIn engine compartment fuse/relay
block. See Fig. 1
& Fig. 2 .
Fuel Pump RelayBehind left front kick panel.
Headlight RelayOn bracket, near master cylinder. See
Fig. 1
.
Headlight Retractor RelayOn bracket, near master cylinder. See
Fig. 1
.
Horn RelayOn bracket, behind left side of dash.
See Fig. 1
.
Ignition RelayIn engine compartment fuse/relay
block.
Turn Signal/Hazard Flasher RelayOn bracket, behind left side of dash.
See Fig. 1
.
ComponentLocation
Fuse BlockBehind left side of dash.
Fuse/Relay BlockIn right rear corner of engine compartment, near firewall.
See Fig. 2
.
Heater Blower Motor Circuit BreakerIn passenger compartment fuse block.

1991 Mazda MX-5 Miata
ELECTRICAL COMPONENT LOCATOR 1991 MAZDA ELECTRICAL COMPONENTS

1991 Mazda MX-5 Miata
ELECTRICAL COMPONENT LOCATOR 1991 MAZDA ELECTRICAL COMPONENTS
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CONTROL UNITS LOCATION
SENDING UNITS & SENSORS
SENDING UNITS & SENSORS LOCATION
MOTORS
MOTORS LOCATION
SOLENOIDS & SOLENOID VALVES
SOLENOIDS & SOLENOID VALVES LOCATION
ComponentLocation
ABS Control UnitBehind center of dash, near ECU.
Cruise Control UnitBehind left side of dash, above fuse block.
Engine Control Unit (ECU)Behind center of dash. See Fig. 2 .
Supplemental Safety Restraint (SRS)
ModuleBehind left side of dash. See Fig. 3 .
ComponentLocation
ABS Wheel SensorsOn each front & rear wheel hub
assembly.
Airflow MeterConnected to air filter housing. See Fig.
2 .
Atmospheric Pressure SensorBuilt-in ECU.
Brake Fluid Level SensorInside brake master cylinder.
Coolant Temperature SensorOn water outlet, at left rear of engine. See
Fig. 2
.
Cooling Fan ThermoswitchOn thermostat housing.
Crank Angle SensorOn right rear side of cylinder head. See
Fig. 2
.
Intake Air ThermosensorIn airflow sensor unit.
Oil Pressure SensorOn left side of engine near oil filter.
SRS Crash/Impact Sensors
FrontOn center, left and right front of
vehicle. See Fig. 3
.
CenterBehind center of dash. See Fig. 3 .
Throttle Position Sensor (TPS)Mounted on side of throttle body. See
Fig. 2
.
ComponentLocation
A/C-Heater Blower MotorBehind left side of dash.
Wiper MotorOn right side of firewall.

1991 Mazda MX-5 Miata
ELECTRICAL COMPONENT LOCATOR 1991 MAZDA ELECTRICAL COMPONENTS
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1 - 30 Amp (Pink) Headlights
2 - 30 Amp (Pink) Fuel Injection, Alternator
3 - 80 Amp (Black) Protection Of All Circuits
4 - 40 Amp (Green) Taillights, Shift Lock, Cruise Control, Horn, Stoplights, Hazard Warning Lights,
Interior Lights, Warning Buzzers, Radio/Cassette, Compact Disc Player, Clock
5 - Empty (1990); 60 Amp (Yellow) (1991-94) Anti-Lock Brake System
6 - 30 Amp (Pink) Cooling Fan
7 - 10 Amp (Red) Air Bag
8 - 20 Amp (Yellow) A/C Additional Fan
9 - 10 Amp (Red) Fuel Injection
10 - 30 Amp (Pink) Headlight Retractor
TRUNK MOUNTED FUSE PANEL IDENTIFICATION

1991 Mazda MX-5 Miata
FUSES & CIRCUIT BREAKERS Fuses & Circuit Breakers 1990-95 Mazda
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Any modification to the exhaust system on turbo models, which reduces exhaust backpressure, will lead to lean
fuel mixtures and excessive spark advance. This could cause serious engine damage.
ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS
ENGINE OIL
FUEL SYSTEM SERVICE
HALOGEN BULBS
Halogen bulbs contain pressurized gas which may explode if overheated. DO NOT touch glass portion of bulb
with bare hands. Eye protection should be worn when handling or working around halogen bulbs.
HEADLIGHT RETRACTOR
RADIATOR CAP
RADIATOR FAN WARNING:Many solid state electrical components can be damaged by static
electricity (ESD). Some will display a warning label, but many will not.
Discharge personal static electricity by touching a metal ground point on
the vehicle prior to servicing any ESD sensitive component.
CAUTION: Never use non-detergent or straight mineral oil.
WARNING:Relieve fuel system pressure prior to servicing any fuel system
component (fuel injection models).
CAUTION: If headlight retractor freezes during cold weather operation, DO NOT
attempt to force mechanism. Headlights should be kept raised at all times
in cold weather. To raise them, use only headlight retractor switch. DO
NOT use headlight switch.
CAUTION: Always disconnect the fan motor when working near the radiator fan. The
fan is temperature controlled and could start at any time even when the
ignition key is in the OFF position. DO NOT loosen or remove radiator cap
when cooling system is hot.
WARNING:Keep hands away from radiator fan. Fan is controlled by a thermostatic
switch which may come on or run for up to 15 minutes even after engine
is turned off.

1991 Mazda MX-5 Miata
FUSES & CIRCUIT BREAKERS Fuses & Circuit Breakers 1990-95 Mazda
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Removal & Installation (MX-6 & 626)
Pry ornament cap from horn pad with wide-blade screwdriver. Remove steering wheel nut. Use a puller to
remove steering wheel. To install, reverse removal procedure.
Removal & Installation (Protege & 323)
Remove 2 horn pad screws from behind steering wheel. Remove horn pad. Remove steering wheel nut. Use a
puller to remove steering wheel. To install, reverse removal procedure.
COMBINATION SWITCH
Removal (Miata & RX7 Convertible)
See STEERING WHEEL & HORN PAD under REMOVAL & INSTALLATION. Remove steering wheel.
Remove column covers. Remove screws and remove combination switch with clockspring connector assembly.
Installation
1. Install combination switch and clockspring assembly. Before installing steering wheel, center
clockspring. To center clockspring, set front wheels straight ahead. Turn clockspring connector clockwise
until it stops. DO NOT force it.
2. Return connector 2 3/4 turns (counterclockwise). Rotate clockspring connector further (if necessary) to
align marks on connector and outer housing. See Fig. 1
.
3. Install steering wheel. Tighten steering wheel nut to specification. See TORQUE SPECIFICATIONS
TABLE at end of article. Install air bag module. See AIR BAG article in the ACCESSORIES/SAFETY
EQUIPMENT section.

1991 Mazda MX-5 Miata
STEERING COLUMN 1991 STEERING Mazda - Steering Columns
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Fig. 1: Aligning Clockspring Connector Alignment Marks
Courtesy of MAZDA MOTORS CORP.
Removal & Installation (All Others)
Remove steering wheel. See STEERING WHEEL & HORN PAD under REMOVAL & INSTALLATION.
Remove steering column covers. Disconnect combination switch connectors. Remove combination switch. To
install, reverse removal procedure.
IGNITION SWITCH & STEERING LOCK
Removal & Installation (All Models)
1. Remove steering wheel and combination switch. See STEERING WHEEL & HORN PAD and
COMBINATION SWITCH.
2. Remove ignition switch connectors. Remove ignition switch-to-steering lock screw. Remove ignition
switch.
3. With a hammer and chisel, make a groove on steering lock assembly shear screws. Remove 2 shear
screws with screwdriver. Remove ignition switch/steering lock assembly. To install, reverse removal
procedure. Tighten NEW shear screws until head breaks off.
STEERING COLUMN
CAUTION: Excessive pressure or impact to mainshaft during service may cause
column to collapse.

1991 Mazda MX-5 Miata
STEERING COLUMN 1991 STEERING Mazda - Steering Columns
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