warning MAZDA MIATA 1991 Factory Owner's Manual

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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FUSES & CIRCUIT BREAKERS
Fuses & Circuit Breakers 1990-95 Mazda
FUSES & CIRCUIT BREAKERS
FUSE PANEL LOCATION
Fuse box is located above driver's left knee, accessible through a removable cover. The main fuse block is
located at the right rear of the engine compartment.
The Trunk Mounted Fuse Panel is located on the right side of the trunk, near the trunk hinge. (1992-95 Models)
MAIN FUSE BLOCK IDENTIFICATION
Fig. 1: Main Fuse Block Identification

Courtesy of MAZDA MOTOR OF AMERICA, INC.
Fuse & Circuit Breaker Identification
WARNING:Always disconnect battery ground cable before servicing "high-current"
fuses. It is recommended that "high-current" fuses be replaced by a
qualified technician.

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

1991 Mazda MX-5 Miata
FUSES & CIRCUIT BREAKERS Fuses & Circuit Breakers 1990-95 Mazda
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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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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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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
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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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HEATER SYSTEM
1990-92 Heater Systems
DESCRIPTION & OPERATION
Heater case, mounted under center of instrument panel, contains airflow mode door and air-mix (temperature
blend) door. See Fig. 1
. Blower case, mounted under right end of instrument panel, contains recirculated/fresh
air door. All doors are controlled manually from control panel by cable.
Blower motor relay, in left rear corner of engine compartment (on relay cluster), supplies power to blower
motor. Blower resistors, on bottom of blower case, determine blower speed.
Fig. 1: Exploded View of Heater Case

Courtesy of MAZDA MOTORS CORP. 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.

1991 Mazda MX-5 Miata
HEATER SYSTEM 1990-92 Heater Systems

1991 Mazda MX-5 Miata
HEATER SYSTEM 1990-92 Heater Systems
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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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Fig. 2: Testing Blower Switch
Courtesy of MAZDA MOTORS CORP.
REMOVAL & INSTALLATION
CONTROL PANEL
Removal & Installation
Remove rear center console assembly. Remove vent outlets from center panel assembly. Remove center panel
assembly. Remove control panel screws. Pull control panel from center panel and disconnect cables. To install,
reverse removal procedure.
HEATER CORE
Removal & Installation
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.

1991 Mazda MX-5 Miata
HEATER SYSTEM 1990-92 Heater Systems
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