1991 MAZDA MIATA electrical

Disconnect electrical connectors from blower case. Remove glove box. Loosen seal plate between blower motor
case and evaporator case. Remove blower motor case nuts. Remove case and seal plate. To install, reverse
removal procedure.
COMPRESSOR
Removal & Installation
1. Disconnect negative battery cable. Discharge A/C system using approved refrigerant recovery/recycling
equipment. Disconnect compressor clutch connector. Disconnect refrigerant lines from compressor.
Remove drive belt.
2. Raise and support vehicle. Remove compressor mounting bolts and remove compressor. To install,
reverse removal procedure. Adjust drive belt to specified tension. Evacuate and charge system.
CONDENSER & RECEIVER-DRIER
Removal & Installation
Discharge A/C system using approved refrigerant recovery/recycling equipment. Raise and support vehicle.
Remove splash shield and air guide. Remove condenser and receiver-drier as an assembly. To install, reverse
removal procedure. Evacuate and charge system.
CONTROL PANEL
Removal & Installation
Remove rear console assembly. See Fig. 4 . Remove vent outlets from center panel assembly. Remove center
panel assembly. Remove control panel screws. Pull control panel from hole. Disconnect door control cables
from back of control panel and remove panel. To install, reverse removal procedure.
EVAPORATOR CORE & THERMOSWITCH
Removal & Installation
1. Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove condenser and
receiver-drier as an assembly. Disconnect low-pressure and high-pressure pipes from evaporator tubes at
engine compartment firewall.
2. Remove right undercover and glove box. Disconnect thermoswitch electrical connector. Loosen left seal
plate (between heater case and evaporator case). Loosen right seal plate (between evaporator case and
blower motor case).
3. Remove evaporator case. Disassemble evaporator case, and remove evaporator core and thermoswitch.
See Fig. 3
. To install, reverse removal procedure. Evacuate and charge system.

1991 Mazda MX-5 Miata
A/C-HEATER SYSTEM - MANUAL 1990-92 Manual A/C-Heater Systems
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STARTER - DIRECT DRIVE
1990-92 ELECTRICAL Mazda Starters - Direct Drive
DESCRIPTION
Nippondenso direct drive starter is a conventional 12-volt, 4-pole, brush-type starter. The integral solenoid is
attached to the drive housing. The overrunning clutch pinion drive is mounted directly on armature shaft drive
end.
TROUBLESHOOTING
TESTING (ON VEHICLE)
CIRCUIT TESTING
1. Turn ignition switch to START position, depress clutch and ensure starter operates. If starter does not
operate, use voltmeter to check voltage at "S" terminal when clutch is depressed and ignition is turned to
START position. See Fig. 1
.
2. If voltage is less than 8 volts, check starter interlock switch and ignition switch to starter wiring circuit for
short to ground. If voltage is greater than 8 volts and starter is inoperative, starter has an internal fault.
Repair or replace as required. NOTE: For information on B2200 and Protege models with automatic transmissions,
see STARTERS - GEAR REDUCTION article.
NOTE: See TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL
INFORMATION section.
NOTE: Before testing, ensure battery is fully charged, battery cables and terminals are
clean and tight and engine grounds are good.

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive
Microsoft
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Microsoft
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Fig. 1: Direct Drive Starter Circuit Diagrams
Courtesy of MAZDA MOTORS CORP.
STARTER INTERLOCK SWITCH (CLUTCH START SWITCH)
Switch is mounted on bracket near top front of clutch pedal. Disconnect switch harness connector. Using
ohmmeter, ensure continuity exists between switch connector terminals when clutch pedal is depressed. If

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive
Microsoft
Sunday, July 05, 2009 2:13:20 PMPage 2 © 2005 Mitchell Repair Information Company, LLC.

continuity does not exist, adjust or replace switch.
BENCH TESTS (ASSEMBLED)
NO-LOAD TEST
Connect fully-charged 12-volt battery, voltmeter and ammeter to starter. See Fig. 2
. Using remote starter wires
or jumper, engage solenoid. Starter should spin smoothly. Note/record meter readings and check no-load
specification. See NO-LOAD TEST SPECIFICATIONS table. If not within specification, disassemble and
inspect starter components.
NO-LOAD TEST SPECIFICATIONS
ApplicationSpecification
B2200 (M/T), Miata, Protege (M/T) & 323
Voltage11.5 Volts
Current60 Amps Maximum
Shaft Speed6500 RPM

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive
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Sunday, July 05, 2009 2:13:20 PMPage 3 © 2005 Mitchell Repair Information Company, LLC.

Fig. 2: Testing Direct Drive Starter Circuits
Courtesy of MAZDA MOTORS CORP.
SOLENOID TESTS

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive
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SOLENOID PULL-IN TEST
Connect positive battery lead to solenoid "S" terminal and negative battery lead to solenoid case. Starter pinion
drive gear should extend quickly and maintain this position. If starter pinion drive gear does not extend, replace
solenoid. See Fig. 2
.
SOLENOID RETURN TEST
Connect positive battery lead to solenoid "M" terminal and ground negative battery lead to starter body. Using
screwdriver, pry overrunning clutch pinion drive outward. Release screwdriver and ensure overrunning clutch
pinion drive returns to original position. See Fig. 2 .
SOLENOID
1. Disconnect all wires to solenoid. Using ohmmeter, ensure continuity between "S" and "M" terminals, and
between "S" terminal and solenoid body. See Fig. 1
. If continuity does not exist between these terminals,
solenoid must be replaced.
2. Next ensure continuity does not exist between "M" and "B" terminals. If continuity exists between these
terminals, solenoid is shorted and must be replaced.
PINION GAP ADJUSTMENT
1. Ensure field wire is disconnected from solenoid "M" terminal. Connect positive battery lead to "S"
terminal and negative battery lead to starter case. Starter pinion drive gear will extend outward and stop.
2. Quickly measure pinion gap clearance between end of pinion drive and circlip retainer. See Fig. 3
. DO
NOT operate starter solenoid for more than 10 seconds. Pinion gap clearance should be .02-.08" (0.5-2.0
mm).
3. If pinion gap clearance is not within specification, adjust by increasing or decreasing thickness of
solenoid shims located between solenoid and drive housin
g. NOTE: Solenoid tests must be performed with starter assembled and field lead ("M"
terminal wire) disconnected at the solenoid.
CAUTION: Do not engage starter solenoid for more than 10 seconds during testing or
damage to coil winding may result.

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive
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Fig. 3: Adjusting Pinion Gap
Courtesy of MAZDA MOTORS CORP.
BENCH TESTING (DISASSEMBLED)

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive
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ARMATURE TESTING
1. Place armature in growler. Turn on growler and hold a piece of hacksaw blade over armature. Slowly
rotate armature. If hacksaw blade is attracted to core or if it vibrates, replace armature.
2. Remove armature from growler. Using an ohmmeter, check continuity between commutator and core. If
continuity exists, the armature is shorted and must be replaced. Check continuity between commutator
and shaft. If continuity exists, replace armature.
3. Check continuity between each commutator segment. If an open exists between any 2 segments, replace
armature.
COMMUTATOR TESTING
1. Clean surface and polish with No. 400 sandpaper if required. If surface is scored, out of round or pitted,
turn commutator in a lathe.
2. Maximum commutator runout and minimum diameter of commutator must not exceed specification after
turning. See COMMUTATOR SPECIFICATIONS table.
3. Commutator mica undercut depth should be .02 -.03" (.5 -.8 mm). Minimum mica undercut depth
is .008" (.20 mm). If not within specification, undercut to standard depth.
COMMUTATOR SPECIFICATIONS
BRUSH TESTING
1. Connect ohmmeter lead to positive brush holder and other lead to negative brush holder. If continuity
exists, brush holder assembly is shorted and must be replaced.
2. Check brush length. If less than specification, replace brushes. See BRUSH LENGTH
SPECIFICATIONS table. Use brush spring scale to check spring tension. Spring tension is measured at
point where spring separates from brush.Tension should be greater than 2 lbs. (0.9 kg). Tension
specification for a new spring is 3.1-5.7 lbs. (1.4-2.6 kg). Brushes must move freely in holders.
BRUSH LENGTH SPECIFICATIONS
FIELD COIL TESTING
1. Connect one ohmmeter lead to field coil lead ("M" terminal lead). Connect other lead to soldered portion
of brush lead. If continuity does not exist, repair or replace field coil.
2. Check field coil for shorts to
ground by connecting ohmmeter lead to field coil lead. Connect other lead
Application
Maximum Runout In.
(mm)Minimum Diameter
In. (mm)
B2200 (M/T)
Protege (M/T) & 323.004 (.10)1.22 (31)
Miata.001 (.03)1.22 (31)
ApplicationStandard In. (mm)Minimum In. (mm)
All Models.67 (17.0).45 (11.5)

1991 Mazda MX-5 Miata
STARTER - DIRECT DRIVE 1990-92 ELECTRICAL Mazda Starters - Direct Drive
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