1991 MAZDA MIATA ignition

ABS SYSTEM TEST TURN IGNITION KEY ON (DO NOT RUN ENGINE
Tester will rapidly display several messages during an Initial Segment Check.
Fig. 15: Test 3 ABS System Test

Courtesy of MAZDA MOTORS CORP.
TEST 4 SYSTEM VOLTAGE TEST

1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
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CHARGING SYSTEM TROUBLE SHOOTING
TROUBLE SHOOTING PRECAUTIONS
Miata
Obtain code number and deactivate audio anti-theft system before disconnecting battery.
All Models
DO NOT reverse battery cable connections. Rectifier will be damaged.
DO NOT use high voltage type testers.
PROBLEM Possible CauseAction
NO START CONDITION
Dead BatteryCheck/Replace Battery
Bad Cable ConnectionsClean/Replace Cables
Ignition Switch/Circuit FaultCheck Switch/Circuit
CHARGING SYSTEM WARNING LIGHT STAYS ON
Loose/Worn Alternator BeltTighten/Replace Belt
Loose Alternator ConnectionsCheck/Repair
Connections
Warning Light WiringCheck/Repair Wiring
Faulty Stator/DiodesTest/Repair Alternator
Faulty Voltage RegulatorTest/Repair Regulator
WARNING LIGHT OFF WITH IGNITION SWITCH ON
Blown FuseCheck/Replace Fuse
Faulty AlternatorTest Alternator
Bad Warning Light BulbTest/Replace Bulb
WARNING LIGHT ON WITH IGNITION SWITCH OFF
Alternator Wiring ShortCheck/Repair Wiring
Faulty Rectifier BridgeTest/Repair Alternator
AMMETER INDICATES DISCHARGE
Loose/Worn Alternator BeltTighten/Replace Belt
Loose Alternator ConnectionsCheck/Repair
Connections
Faulty AmmeterTest/Replace Ammeter
NOISY Defective BatteryReplace Battery
Defective AlternatorTest/Repair Alternator
Defective RegulatorTest/Repair Regulator
NOTE: Observe the following precautions when trouble shooting or testing charging
system:

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
Microsoft
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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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ANTI-LOCK BRAKE SYSTEM
The anti-lock brake system contains electronic equipment that can be susceptible to interference caused by
improperly installed or high output radio transmitting equipment. Since this interference could cause the
possible loss of the anti-lock braking capability, such equipment should be installed by qualified professionals.
On models equipped with anti-lock brake systems, ALWAYS observe the following cautions:
DO NOT attempt to bleed hydraulic system without first referring to the appropriate ANTI-LOCK
BRAKE SYSTEM article in the BRAKES Section.
DO NOT mix tire sizes. As long as tires remain close to the original diameter, increasing the width is
acceptable. Rolling diameter must be identical for all 4 tires. Some manufacturers recommend tires of the
same brand, style and type. Failure to follow this precaution may cause inaccurate wheel speed readings.
Use ONLY recommended brake fluids. DO NOT use silicone brake fluids in an ABS-equipped vehicle.
BATTERY WARNING
REPLACING BLOWN FUSES
Before replacing a blown fuse, remove ignition key, turn off all lights and accessories to avoid damaging the
electrical system. Be sure to use fuse with the correct indicated amperage rating. The use of an incorrect
amperage rating fuse may result in a dangerous electrical system overload.
BRAKE PAD WEAR INDICATOR
Indicator will cause a squealing or scraping noise, warning that brake pads need replacement.
CATALYTIC CONVERTER
Continued operation of vehicle with a severe malfunction could cause converter to overheat, resulting in
possible damage to converter and vehicle. service.
WARNING:R-134a service equipment or vehicle A/C systems SHOULD NOT be
pressure tested or leak tested with compressed air. Some mixtures of
air/R134a have shown to be combustible at elevated pressures. These
mixtures are dangerous and may cause fire and/or explosions. See AIR
CONDITIONING SERVICE article in GENERAL INFORMATION section.
WARNING: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 GENERAL
INFORMATION section.

1991 Mazda MX-5 Miata
FUSES & CIRCUIT BREAKERS Fuses & Circuit Breakers 1990-95 Mazda
Microsoft
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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
Microsoft
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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
Microsoft
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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
Microsoft
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