1997 MAZDA MX-5 heater

2. Drain cooling system. Remove dashboard. Remove heater unit. SAS unit connectors. Remove 4 SAS unit
mounting bracket nuts. Remove 2 SAS unit retaining screws. Remove SAS unit. See Fig. 9
.
Installation
To install, reverse removal procedure. Position SAS unit and bracket with arrow toward front of vehicle.
Tighten fasteners to specification. See TORQUE SPECIFICATIONS
. After SAS unit is installed, activate air
bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Check AIR BAG warning light to
ensure system is functioning properly. See SYSTEM OPERATION CHECK
.
CLOCKSPRING
Removal
1. Set front wheels in straight-ahead position. Before proceeding, see SERVICE PRECAUTIONS .
Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
.
2. Remove driver-side air bag module. See DRIVER
-SIDE AIR BAG MODULE . Remove steering wheel
nut. Using a puller, remove steering wheel. Remove steering column covers. Remove clockspring screws.
Remove clockspring and combination switch as an assembly.
Installation
1. To install, reverse removal procedure. Tighten steering wheel nut to specification. See TORQUE
SPECIFICATIONS .
2. After installation, activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
.
Check AIR BAG warning light to ensure system is functioning properly. See SYSTEM OPERATION
CHECK .
SAS UNIT
Removal
1. Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING &
ACTIVATING AIR BAG SYSTEM .
2. SAS unit is located under center of dashboard. See Fig. 1
. Remove dashboard. Remove heater assembly.
Disconnect SAS unit connectors. Remove 4 SAS unit mounting bracket nuts. Remove 2 SAS unit
retainin
g screws. Remove SAS unit. See Fig. 9. NOTE: Clockspring is part of combination switch. When replacing clockspring, replace
the clockspring and combination switch as an assembly.

1997 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT Mazda - Air Bag Restraint System
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1. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Remove meter
hood. Ensure instrument cluster 12 pin connector is securely connected and that terminal No. 1 E is not
damaged. Check continuity between terminal No. 1E of 12 pin cluster connector and terminal No. 2K of
print plate of instrument cluster. If there is continuity, go to next step. If there is no continuity, replace
print plate and then go to next step.
2. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Check if terminal
No. Q of 21 pin SAS unit connector is securely connected and is not damaged. If ok, go to next step. If
terminal Q is not securely connected or is damaged, replace air bag harness, then go to next step.
3. Disconnect 21 pin SAS unit connector and 12 pin instrument cluster connector. Check continuity between
terminal No. Q of SAS unit connector and terminal No. 1 E of instrument cluster connector. If there is
continuity, replace SAS unit and then go to next step. See SAS UNIT
under REMOVAL &
INSTALLATION. If there is no continuity, go to next step.
4. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Check AIR BAG
warning light for proper system function. See SYSTEM OPERATION CHECK
.
WARNING LIGHT DOES NOT COME ON
Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Remove meter hood.
Ensure instrument cluster 12 pin connector is securely connected and that terminal No. 1 E is not damaged.
Check continuity between terminal No. 1E of 12 pin cluster connector and terminal No. 2K of print plate of
instrument cluster. If there is continuity, go to next step. If there is no continuity, replace print plate and then go
to next step.
WARNING LIGHT REMAINS ON
1. Measure battery voltage. If voltage is more than 9 volts, go to next step. If voltage is not more than 9
volts, check charging system.
2. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Remove dashboard.
Remove heater unit. Check if SAS unit connector is securely connected. Check short bar between SAS
unit terminal No. Q and terminal No. S. If short bar is bent, replace wiring harness and then go to next
step. If short bar is OK, go to next step.
3. Check short bar hook on SAS unit. If hook is OK, go to next step. If hook is damaged, replace SAS unit.
See SAS UNIT
under REMOVAL & INSTALLATION.
4. Disconnect SAS unit 21 pin connector and instrument panel 12 pin connector. Carefully insert an
insulation material between terminal No. Q and terminal No. S of SAS unit so short bar cannot move. NOTE: For connector terminal identification, see WIRING DIAGRAM
.
NOTE: For connector terminal identification, see WIRING DIAGRAM
.
NOTE: For connector terminal identification, see WIRING DIAGRAM
.
NOTE: Use care not to damage short bar when inserting insulation material.

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AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT Mazda - Air Bag Restraint System
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5. Check continuity between terminal No. Q and ground. If continuity exists, replace or repair wiring
harness between instrument cluster and SAS unit. If no continuity exists, replace SAS unit. See SAS
UNIT under REMOVAL & INSTALLATION.
6. Activate air bag system and perform SYSTEM OPERATION CHECK
. Check that AIR BAG warning
light is operating properly. If not, reconfirm malfunction symptoms.
DTC 0 - SAS UNIT
1. Disable system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Remove dashboard.
Remove heater unit. Check if SAS unit connector is securely connected. If not, reconnect connector and
go next step. If ok, go to next step.
2. Disconnect SAS unit connector and check for continuity between terminal No. V and terminal No. Y of
SAS unit connector. If there is continuity, replace SAS unit. If there is no continuity, replace wiring
harness. Perform SYSTEM OPERATION CHECK
.
DTC 3 - BATTERY
1. Check that battery voltage is at least 8 volts. If not, check battery and/or charging system. Turn ignition
on and check voltage at joint connector terminals A or E (X-33).
2. If voltage is over 8 volts, replace SAS unit. See SAS UNIT
under REMOVAL & INSTALLATION. If
voltage is not over 8 volts, replace wiring harness from battery to fuse box. Perform SYSTEM
OPERATION CHECK .
DTC 6 - DRIVER-SIDE AIR BAG MODULE
1. Disable air ba
g system. See procedures under DISABLING & ACTIVATING AIR BAG SYSTEM. NOTE: When air bag warning light remains on, it can indicate a DTC 0 caused by no
continuity between terminal No. V and terminal No. Y of SAS unit This can be
due to a damaged SAS unit, an open or short circuit in wiring harness or poor
connections.
NOTE: For connector terminal identification, see WIRING DIAGRAM
.
NOTE: When voltage supplied to SAS unit is less than 1 volt due to weak battery, open
or short in wiring harness, poor connection of connector or damaged SAS unit,
DTC 3 will set
NOTE: For connector terminal identification, see WIRING DIAGRAM
.
NOTE: When resistance Is detected between terminals M-O of SAS unit is NOT 2 ohms,
DTC 6 will set.
NOTE: For connector terminal identification, see WIRING DIAGRAM
.

1997 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT Mazda - Air Bag Restraint System
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Remove driver-side air bag module. See DRIVER-SIDE AIR BAG MODULE under REMOVAL &
INSTALLATION.
2. Inspect clockspring connectors for damage. If connectors are okay, go to next step. If connectors are
damaged, replace clockspring. Perform SYSTEM OPERATION CHECK
.
3. Connect Special Service Tool (49 0839 285) to terminal No. 3B and terminal No. 3C of clockspring. Set
SST resistance to 2 ohms. Connect clockspring connector. Connect negative battery cable. Turn ignition
switch to ON position and cheek for codes. If CODE 6 is displayed, go to next step. If CODE 6 is not
present, replace driver-side air bag module. Perform SYSTEM OPERATION CHECK
.
4. Turn ignition switch to LOCK position. Disconnect negative battery cable and wait for 1 minute.
Disconnect clockspring connector and inspect. If pins are ok go next step. If pins are damaged, replace
wiring harness from clockspring to SAS unit.
5. Connect Special Service Tool (49 0839 285) to terminal No. A and terminal No. B of clockspring
connector. Set SST resistance to 2 ohms. Connect clockspring connector and connect negative battery
cable. Turn ignition switch to ON position and cheek for codes. If CODE 6 is displayed, go to next step.
If CODE 6 is not present, replace clockspring. See CLOCKSPRING
under REMOVAL &
INSTALLATION. Perform SYSTEM OPERATION CHECK
.
6. Turn ignition switch to LOCK position. Disconnect negative battery cable. Wait for 1 minute. Remove
dashboard and heater unit. Disconnect SAS unit connector.
7. Check wiring harness between terminal No. O of SAS unit connector and between terminal No. A of
clockspring connector. Also check between terminal No. M of SAS unit connector and terminal No. B of
clockspring connector. Check for short to ground, short to power or open circuit. If wiring is OK, replace
SAS unit. See SAS UNIT
under REMOVAL & INSTALLATION.If wiring is not OK, replace wiring
harness from clockspring to SAS unit. Perform SYSTEM OPERATION CHECK
.
DTC 7 - PASSENGER-SIDE AIR BAG MODULE
1. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM
. Inspect passenger-
side air bag module connectors for damage. If connectors are okay, go to next step. If connectors are
damaged, replace wiring harness from passenger-side air bag module to SAS unit. Perform SYSTEM
OPERATION CHECK .
2. Connect Special Service Tool (49 0839 285) to terminal No A and terminal No. B of passenger-side air
bag module connector. Set Special Service Tool resistance to 2 ohms. Connect clockspring connector.
Connect negative battery cable. Turn ignition switch to ON position and check for codes. If DTC 7 is
displayed, go to next step. If CODE 7 is not present replace passenger-side air bag module. See
PASSENGER
-SIDE AIR BAG MODULE under REMOVAL & INSTALLATION. Perform SYSTEM
OPERATION CHECK .
3. Turn ignition switch to LOCK position. Disconnect negative battery cable and wait 1 minute. Disconnect
clocksprin
g connector. Remove dashboard and heater unit. NOTE: For connector terminal identification, see WIRING DIAGRAM
.
NOTE: When resistance is detected between terminals l-K of SAS unit is NOT 2 ohms
and/or there is no continuity between terminal No. E of SAS unit and ground,
DTC 7 will set

1997 Mazda MX-5 Miata
AIR BAG RESTRAINT SYSTEM 1997 ACCESSORIES/SAFETY EQUIPMENT Mazda - Air Bag Restraint System
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CONNECTORS
CONNECTORS
GROUNDS
GROUNDS
Data Link Connector (DLC)On left inner fender panel. See Fig. 1 .
Data Link Connector (DLC) No. 2Under left side, center of dash, near console. See Fig. 4 .
Ignition CoilOn center rear of engine compartment.
Power ConnectorOn left inner fender panel.
Resistor (A/C-Heater)Under right side of dash. See Fig. 2 .
ComponentComponent Location
X-06 (White, 1 Pin)At right rear of engine compartment.
X-07 (White, 1 Pin)At right rear of engine compartment.
X-08 (White, 3 Pin)At right rear of engine compartment.
X-09 (Green, 4 Pin)At right rear of engine compartment.
X-10 (White, 6 Pin)At right rear of engine compartment.
X-12 (A/T) (White, 4 Pin)At right rear of engine compartment. See Fig. 1 .
X-12 (M/T) (Black, 1 Pin)At right rear of engine compartment. See Fig. 1 .
X-13 (Black, 10 Pin)At right rear of engine compartment. See Fig. 1 .
X-14 (Black, 8 Pin)At right rear of engine. See Fig. 1 .
X-15 (Gray, 4 Pin)At right rear of engine. See Fig. 1 .
X-16 (White, 20 Pin)At right kick panel. See Fig. 2 .
X-17 (White, 20 Pin)At right kick panel. See Fig. 2 .
X-18 (White, 24 Pin)At right kick panel. See Fig. 2 .
X-19 (White, 20 Pin)At right kick panel. See Fig. 2 .
X-20 (White, 20 Pin)At left side of dash. See Fig. 4 .
X-21 (White, 24 Pin)At left side of dash. See Fig. 4 .
X-22 (White, 2 Pin)At left side of dash. See Fig. 4 .
X-23 (White, 16 Pin)At right side of dash. See Fig. 4 .
X-24 (White, 12 Pin)At left kick panel. See Fig. 2 .
X-25 (White, 12 Pin)At left kick panel. See Fig. 2 .
X-26 (White, 4 Pin)At left kick panel. See Fig. 2 .
X-27 (White, 3 Pin)At left kick panel. See Fig. 2 .
X-28 (White, 4 Pin)At right kick panel. See Fig. 2 .
X-29 (White, 3 Pin)At right kick panel. See Fig. 2 .
X-30 (White, 8 Pin)Forward of right rear wheelwell. See Fig. 3 .
X-31 (White, 2 Pin)At right front corner of trunk.
X-36 (White, 2 Pin)At left kick panel.

1997 Mazda MX-5 Miata
1997 MAZDA MX-5 Miata
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HEATER SYSTEM
1997 Heater System
DESCRIPTION & OPERATION
Heater case, mounted under center of instrument panel, contains airflow mode doors and air-mix (temperature
blend) doors. See Fig. 1
. Blower case, mounted under right side of instrument panel, contains blower motor,
blower resistor and fresh/recirculated air door. All doors are controlled manually from control panel by cable.
Blower resistors, located on bottom of blower case, determine blower speed. 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.
CAUTION: When battery is disconnected, radio will go into anti-theft protection
mode. Obtain radio anti-theft protection code from owner prior to
servicing vehicle.

1997 Mazda MX-5 Miata
HEATER SYSTEM 1997 Heater System

1997 Mazda MX-5 Miata
HEATER SYSTEM 1997 Heater System
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Fig. 1: Exploded View Of Heater Unit
Courtesy of MAZDA MOTORS CORP.
ADJUSTMENTS
AIRFLOW MODE DOOR
Set airflow mode control lever at vent position. Disconnect control cable at airflow mode door lever. See Fig.
1 . Extend airflow mode door lever until it stops. Attach control cable to door lever. Secure cable using clip.
Ensure control lever slides freely between defrost and vent positions.
AIR-MIX (TEMPERATURE BLEND) DOOR
Set temperature control lever at maximum hot setting. Disconnect control cable at air-mix door lever. See Fig.
1 . Extend air-mix door lever until it stops. Attach control cable to door lever. Secure cable using clip. Ensure
control lever slides freely between hot and cold settings.
FRESH/RECIRCULATED AIR DOOR
Set fresh/recirculated air control lever at fresh air setting. Disconnect control cable at fresh/recirculated air door
lever. Retract recirculated/fresh air door lever until it stops. Attach control cable to door lever. Secure cable
using clip. Ensure control lever slides freely between recirculated air and fresh air settings.
TESTING
BLOWER MOTOR CIRCUIT
1. Check 30-amp HEATER fuse in passenger compartment fuse block. If fuse is okay, go to next step. If
fuse is burnt, check for short circuit in wiring harness and repair as necessary. Replace fuse.
2. Turn ignition on. Turn blower switch to 4th position (high). Using voltmeter, backprobe Blue wire
terminal of blower motor connector on bottom of blower case. If battery voltage exists, go to next step. If
battery voltage is not present, repair wiring harness between circuit breaker or fuse and blower motor.
3. Ensure ignition is on. Backprobe Blue wire terminal of blower resistor 1-pin connector. If battery voltage
exists, go to next step. If battery voltage is not present, replace blower motor.
4. Backprobe Blue/White wire terminal, Blue/Red wire terminal, Blue/Green wire terminal and Blue/Yellow
wire terminal of blower resistor 4-pin connector. If battery voltage exists, go to next step. If battery
voltage is not present at any terminal, replace blower resistor.
5. Turn blower switch to 4th position (high). Backprobe Black wire terminal of blower switch connector. If
battery voltage is not present, go to next step. If battery voltage exists, repair Black wire between blower
switch and chassis
ground. 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.

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HEATER SYSTEM 1997 Heater System
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6. Turn ignition blower switch off. Backprobe Blue/White wire terminal, Blue/Red wire terminal,
Blue/Green wire terminal and Blue/Yellow wire terminal of blower switch connector If battery voltage is
not present, repair open wire(s) between blower resistor and blower switch. If battery voltage exists,
check blower motor.
BLOWER MOTOR
Disconnect blower motor 2-pin connector from bottom of blower case. Apply battery voltage across blower
motor terminals. Replace blower motor if it does not operate.
BLOWER RESISTOR
Disconnect blower resistor connectors from blower case. Check continuity, in turn, between Blue wire terminal
of 1-pin connector and each terminal of 4-pin connector. Ensure continuity exists. Replace resistor if continuity
does not exist.
BLOWER SWITCH
Disconnect blower switch connector. Place blower switch in indicated positions, and check continuity between
specified blower switch terminals. See BLOWER SWITCH TEST table. See Fig. 2
. If continuity is not as
specified, replace blower switch.
BLOWER SWITCH TEST
Switch PositionContinuity Between Terminals
Off(1)
Low"A" & "G"
Medium-Low"C", "G" & "H"
Medium-High"E", "G" & "H"
High"B", "G" & "H"
(1)There should not be continuity between any terminals.

1997 Mazda MX-5 Miata
HEATER SYSTEM 1997 Heater System
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