relay MAZDA MX-5 1997 Factory User Guide

removal procedure. Tighten mounting bolt to specification. See TORQUE SPECIFICATIONS.
VALVE & MOTOR RELAYS
Removal & Installation
Disconnect negative battery cable. Remove relay cover from hydraulic unit. Remove valve and motor relays.
See Fig. 14
. To install, reverse removal procedure.
Fig. 14: Locating Valve Relay & Motor Relay

Courtesy of MAZDA MOTORS CORP.
ADJUSTMENTS
MASTER CYLINDER PUSH ROD
1. Before installing master cylinder, measure clearance between master cylinder piston and power brake unit
push rod. Turn adjusting nut on Adjustment Gauge (49-B043-001) clockwise to fully retract gauge rod.
Place adjustment gauge onto power brake unit and tighten mounting nuts to 88-138 INCH lbs. (9.9-15.6
N.m).
2. Using a hand-held vacuum pump, apply 19.7 in. Hg to power brake unit. Turn adjusting gauge nut
counterclockwise until
gauge rod just contacts push rod end of power brake unit. Perform STEP 1. See

1997 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1997 BRAKES Mazda - Anti-Lock
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1997 MAZDA
MX-5 Miata
BUZZERS, RELAYS & TIMERS
BUZZERS, RELAYS & TIMERS
CIRCUIT PROTECTION DEVICES
CIRCUIT PROTECTION DEVICES
CONTROL UNITS
CONTROL UNITS
ComponentComponent Location
A/C RelayIn right front of engine compartment, near radiator. See Fig. 1 .
Condenser Fan RelayIn right front of engine compartment, near radiator. See Fig. 1 .
Cooling Fan RelayIn main fuse/relay block.
Flasher UnitBehind left side of dash. See Fig. 2 .
Fuel Pump RelayUnder left side of dash. See Fig. 2 .
Headlamp RelayOn left rear corner of front inner fender panel. See Fig. 1 .
Horn RelayOn left rear corner of front inner fender panel. See Fig. 1 .
INT RelayIntegral with windshield wiper & washer switch.
Main RelayIn left rear corner of engine compartment, in main fuse/relay block.
Power Antenna RelayIn right rear of vehicle, attached to power antenna.
Rear Window Defogger
RelayIn center rear of trunk compartment. See Fig. 3 .
Retractable Headlamp RelayBehind left side of dash.
TNS RelayIn left rear corner of engine compartment, on inner fender panel. See Fig.
1 .
Warning UnitBehind left side of dash. See Fig. 2 .
ComponentComponent Location
Fuse Block (Front)Behind left side of dash. See Fig. 2 .
Fuse Block (Rear)On right rear side of luggage compartment. See Fig. 3 .
Main Fuse BlockOn right rear corner of engine compartment, near firewall. See Fig. 1 .
ComponentComponent Location
ABS Control ModuleBehind passenger's seat. See Fig. 3 .
ABS Control UnitIn right rear corner of engine compartment.
Cruise Control ModuleUnder left side of dash above fuse block. See Fig. 2 .
Daytime Running Lamp (DRL) Control ModuleOn bracket, behind left side of dash. See Fig. 2 .
Engine Control Module (ECM)Behind passenger's seat. See Fig. 3 .

1997 Mazda MX-5 Miata
1997 MAZDA MX-5 Miata

1997 Mazda MX-5 Miata
1997 MAZDA MX-5 Miata
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1997-98 ENGINES
1.8L 4-Cylinder
ENGINE IDENTIFICATION
Engines can be identified by engine model and number. See ENGINE IDENTIFICATION CODE. On Miata,
engine model and number are stamped on flange at upper right rear of cylinder block deck, as viewed from
flywheel. On Protege, engine model and number are stamped on flange at upper left rear of cylinder block deck,
as viewed from flywheel.
ENGINE IDENTIFICATION CODE
ADJUSTMENTS
VALVE CLEARANCE ADJUSTMENT
REMOVAL & INSTALLATION
FUEL PRESSURE RELEASE & PRIMING
Releasing Pressure (Miata)
Locate and remove fuel pump relay from under left side of dash, near steering column. Start engine and allow to
stall. After engine stalls, attempt to restart engine to ensure no residual pressure exists. Turn ignition off and
reinstall fuel pump relay. When disconnecting fuel hoses, cover connection with shop rag to catch fuel leakage.
To avoid excessive cranking after servicing, prime fuel system before starting engine.
Releasing Pressure (Protege)
NOTE: For repair procedures not covered in this article, see ENGINE OVERHAUL
PROCEDURES article in GENERAL INFORMATION.
ApplicationCode
Miata & Protege (1.8L DOHC)BP
NOTE: Valve clearance is not adjustable. Some Hydraulic Lash Adjuster (HLA) noise
may occur during engine start-up. Noise should disappear after engine reaches
normal operating temperature. If noise persists and oil level is okay, change
engine oil. If oil change does not reduce noise, check with manufacturer for
modified HLA.
NOTE: For reassembly reference, label all electrical connectors, vacuum hoses and
fuel lines before removal. Also place mating marks on engine hood and other
major assemblies before removal.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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ELECTRICAL COMPONENT LOCATIONS
OPERATION
All air control doors are controlled manually by cable from control panel. Blower resistor determines blower
speed. With blower switch in high position, blower motor is grounded directly through blower switch. With
blower switch in all other positions, blower motor is grounded through blower resistor and blower switch.
A/C compressor clutch circuit is completed when A/C relay is energized and pressure switch is closed. A/C
relay is energized when Powertrain Control Module (PCM) grounds the solenoid circuit of the relay. The PCM
energizes A/C relay if evaporator thermoswitch is closed and A/C and blower switches are on. The PCM also
controls A/C relay operation according to engine load.
ADJUSTMENTS
TESTING
A/C SYSTEM PERFORMANCE
1. Connect manifold gauge set. Operate engine at 1500 RPM. Operate A/C at maximum cooling, recirculate,
fan on high, vent mode. Close all doors and windows. Place thermometer at center vent outlet.
2. Allow A/C to stabilize. Ensure high pressure is 200-227 psi (14.0-16.0 kg/cm
2 ). Read temperature at
center vent outlet. Ensure temperature is within 39-43°F (3-6°C)
A/C COMPRESSOR CLUTCH CIRCUIT
ComponentLocation
A/C RelayRight Front Corner Of Engine Compartment
Condenser FanRight Front Corner Of Engine Compartment
Blower ResistorBottom Of Blower Case
Evaporator ThermoswitchOn Evaporator Upper Case
Pressure SwitchIn High-Pressure Line, Between Receiver-Drier &
Evaporator
NOTE: For door control cable adjustments, see ADJUSTMENTS in HEATER SYSTEM

article.
WARNING:To avoid injury from accidental air bag deployment, read and follow all
SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG
SYSTEM procedures in AIR BAG RESTRAINT SYSTEM article in the
ACCESSORIES/SAFETY EQUIPMENT section.
NOTE: For test procedures not covered in this article, see TESTING in HEATER
SYSTEM article.

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1. Check WIPER fuse (20-amp) in passenger compartment fuse block. Check AD FAN (additional fan) fuse
(20-amp) in engine compartment fuse block. If fuses are okay, go to next step. If either fuse is blown,
check for shorted wiring harness before replacing fuse.
2. Operate engine at idle. Turn A/C and blower on. Using voltmeter, backprobe Black/Red wire terminal of
compressor clutch connector. If battery voltage exists, replace compressor clutch. If battery voltage is not
present, go to next step.
3. Ensure engine is running. Ensure A/C and blower are on. Using a voltmeter, backprobe Blue/Yellow wire
terminal of the A/C relay connector. If battery voltage exists, go to next step. If battery voltage does not
exist, repair open Blue/Yellow wire between AD FAN fuse and A/C relay.
4. Backprobe Blue wire terminal of A/C relay connector. If battery voltage exists, go to next step. If battery
voltage is not present, repair open Blue wire between WIPER fuse and A/C relay.
5. Backprobe Black/Red wire terminal of A/C relay connector. If battery voltage exists, repair open
Black/Red wire between A/C relay and compressor clutch. If battery voltage is not present, go to next
step.
6. Backprobe Blue/Black wire terminal of A/C relay connector. If voltage is Zero volts, replace A/C relay. I
f
voltage is not Zero volts, repair open Blue/Black wire between A/C relay and PCM. If wire is okay, check
PCM operation.
CONDENSER (ADDITIONAL) FAN CIRCUIT
1. Check ENGINE fuse (30-amp) in passenger compartment fuse block. Check AD FAN fuse (20-amp) in
engine compartment fuse block. If fuses are okay, go to next step. If either fuse is blown, check for
shorted wiring harness before replacing fuse.
2. Start engine. Turn A/C and blower switches on. Using voltmeter, backprobe Black/Yellow wire terminal
of condenser fan motor. If battery voltage exists, go to next step. If battery voltage is not present, go to
step 4).
3. Turn ignition switch off. Disconnect condenser fan connector. Using ohmmeter, check continuity
between Black wire of condenser fan connector and ground. If continuity exists, replace condenser fan. If
continuity is not present, repair open Black wire between condenser fan and ground.
4. Turn ignition on. Ensure A/C and blower switches are on. Using voltmeter, backprobe Black/White wire
terminal of condenser fan relay connector. If battery voltage exists, go to next step. If battery voltage is
not present, repair open Black/White wire between ENGINE fuse and condenser fan relay.
5. Backprobe Blue/Yellow wire terminal of condenser fan relay connector. If battery voltage exists, go to
next step. If battery voltage is not present, repair open Blue/Yellow wire between AD FAN fuse and
condenser fan relay.
6. Backprobe Black/Yellow wire terminal of condenser fan relay connector. If battery voltage exists, repair
open Black/Yellow wire between condenser fan relay and condenser fan. If battery voltage is not present,
go to next step.
7. Backprobe Blue/White wire terminal of condenser fan relay connector. If battery voltage exists, repair
Blue/White wire between condenser fan relay and PCM. If wire is okay, check PCM operation. If battery
voltage is not present, replace condenser fan relay.
A/C SWITCH

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A/C-HEATER SYSTEM - MANUAL 1997 Manual A/C-Heater System
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Disconnect A/C switch connector. Turn A/C switch on. Check continuity between indicated terminals. See A/C
SWITCH TEST table. See Fig. 1 . Replace A/C switch if continuity is not as specified.
A/C SWITCH TEST
Fig. 1: Identifying A/C Switch Terminals

Courtesy of MAZDA MOTORS CORP.
A/C RELAY
Remove relay. Check continuity between indicated relay terminals. See A/C RELAY TEST table. See Fig. 2
.
Replace relay if continuity is not as specified.
A/C RELAY TEST
TerminalContinuity
"D" & "A"(1) Yes
"F" & "A"(1) Yes
(1)Continuity exists in only one direction.
Test Between TerminalsContinuity
"A" & "B"(1) Yes
"C" & "D"(1) No
"C" & "D"(2) Yes
(1)With no voltage applied.
(2)With battery voltage applied to terminals "A" and "B".

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Fig. 2: Identifying A/C Relay Terminals
Courtesy of MAZDA MOTORS CORP.
CONDENSER FAN RELAY
Remove condenser fan relay. Check continuity between indicated relay terminals. See CONDENSER FAN
RELAY TEST table. See Fig. 3 . If continuity is not as specified, replace relay.
CONDENSER FAN RELAY TEST
Test Between TerminalsContinuity
"A" & "B"(1) Yes
"C" & "E"(1) No
"C" & "F"(1) Yes
"C" & "E"(2) Yes
(1)With no voltage applied.
(2)With battery voltage applied to terminals "A" and "B".

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A/C-HEATER SYSTEM - MANUAL 1997 Manual A/C-Heater System
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Fig. 3: Identifying Condenser Fan Relay Terminals
Courtesy of MAZDA MOTORS CORP.
CONDENSER FAN MOTOR
Disconnect condenser fan motor connector. Connect positive battery lead to condenser fan motor Black/Yellow
wire terminal, and ground Black wire terminal. Replace condenser fan motor if it does not operate.
EVAPORATOR THERMOSWITCH
1. Remove glove box. Operate engine at idle. Turn A/C off. Turn blower switch to 4th position (high) for a
few minutes to ensure evaporator temperature is greater than 32°F (0°C). Turn blower switch and engine
off.
2. Disconnect evaporator thermoswitch connector. Check continuity between thermoswitch terminals. If
continuity exists, go to next step. If there is no continuity, replace thermoswitch.
3. Submerge thermoswitch sensing bulb in ice cold water of less than 32°F (0°C). Ensure continuity does
not exist between thermoswitch terminals. Replace thermoswitch if continuity is not as specified.
PRESSURE SWITCH
1. Turn ignition off. Connect manifold pressure gauge set to system. If high-side pressure is 37-310 psi (2.6-
22.0 kg/cm
2 ), go to next step. If pressure is not as specified, check refrigerant level.
2. Disconnect pressure switch connector. Check continuity between switch terminals. If continuity exists,
pressure switch is okay. If there is no continuity, replace pressure switch.
REMOVAL & INSTALLATION

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