1991 MAZDA MIATA alternator

TEST 1. CONNECTION POWER UP
CONNECTION/POWER-UP
1. Locate ABS Control Unit.
2. Disconnect Control Unit Harness from Control Unit.
3. Connect ABS Tester Harness to Control Unit Harness Connector.
4. Turn Ignition Key to "ON" position.
TEST 2 ALTERNATOR TEST
ALTERNATOR TEST START ENGINE (ALTERNATOR TESTED BY RUNNING ENGINE)
Tester will rapidly display several messages during an Initial Segment Check.
Fig. 14: Test 2 Alternator Test

Courtesy of MAZDA MOTORS CORP.
TEST 3 ABS SYSTEM TEST

1991 Mazda MX-5 Miata
ANTI-LOCK BRAKE SYSTEM 1988-91 BRAKES Mazda Anti-Lock Brake System
Microsoft
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ALTERNATOR & REGULATOR
1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
DESCRIPTION
Alternators are conventional 3-phase, self-rectifying type units containing 6 diodes (3 positive and 3 negative)
which are used to rectify current. See Fig. 1
. An internally-mounted, Integrated Circuit (IC) regulator is used
on all models.
Fig. 1: Charging System Wiring Schematic

Courtesy of MAZDA MOTORS CORP.
ADJUSTMENTS
BELT DEFLECTION
Measure belt deflection in center of longest pulley-to-pulley span. See BELT DEFLECTION
SPECIFICATIONS table. If belt deflection is not as specified, adjust as necessary.
BELT DEFLECTION SPECIFICATIONS
ApplicationDeflection - In. (mm)

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
Microsoft
Sunday, July 05, 2009 2:14:53 PMPage 1 © 2005 Mitchell Repair Information Company, LLC.
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Sunday, July 05, 2009 2:14:58 PMPage 1 © 2005 Mitchell Repair Information Company, LLC.

TROUBLE SHOOTING
CHARGING SYSTEM
B2200
New Belt0.28-0.31 (7.0-8.0)
Used Belt0.31-0.35 (8.0-9.0)
B2600i
New Belt0.39-0.47 (10.0-12.0)
Used Belt0.43-0.51 (11.0-13.0)
Miata
New Belt0.31-0.35 (8.0-9.0)
Used Belt0.35-0.39 (9.0-10.0)
MPV
4-Cylinder Engine
New Belt0.39-0.47 (10-12)
Used Belt0.43-0.57 (11-13)
V6 Engine
New Belt0.35-0.39 (9-10)
Used Belt0.39-0.47 (10-12)
MX-3
4-Cylinder Engine
New Belt0.31-0.35 (8.0-9.0)
Used Belt0.35-0.39 (9.0-10.0)
V6 Engine
New Belt0.24-0.28 (6.0-7.0)
Used Belt0.28-0.31 (7.0-8.0)
MX-6 & 626
New Belt0.24-0.31 (6.0-8.0)
Used Belt0.28-0.35 (7.0-9.0)
Protege & 323
New Belt0.31-0.35 (8.0-9.0)
Used Belt0.35-0.39 (9.0-10.0)
RX7
New Belt0.47-0.59 (12.0-15.0)
Used Belt0.55-0.67 (14.0-17.0)
929
New Belt0.35-0.39 (9.0-10.0)
Used Belt0.39-0.47 (10.0-12.0)
- With 22 lbs. (98N) applied to belt.

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
Microsoft
Sunday, July 05, 2009 2:14:54 PMPage 2 © 2005 Mitchell Repair Information Company, LLC.

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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Sunday, July 05, 2009 2:14:54 PMPage 3 © 2005 Mitchell Repair Information Company, LLC.

Battery voltage is always applied to terminal "B".
DO NOT ground terminal "L" while engine is running.
DO NOT start engine with connector disconnected from terminals "L" and "S".
DO NOT apply battery voltage to terminal "L".
ON-VEHICLE TESTING
ALTERNATOR OUTPUT
1. Connect an ammeter (80-amp minimum) in-line between terminal "B" connector and wire. See Fig. 2
,
Fig. 3
and Fig. 4 . Turn all headlights and accessories on and depress brake pedal. With engine operating
at 2500-3000 RPM, measure output amperage. NOTE: Check alternator wiring harness connections and drive belt tension. Battery
must be fully charged before testing. Wait at least 30 seconds after starting
engine before measuring system voltage.
CAUTION: Ensure alternator terminal "B" does not contact ground.

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
Microsoft
Sunday, July 05, 2009 2:14:54 PMPage 4 © 2005 Mitchell Repair Information Company, LLC.

Fig. 2: Identifying Alternator Terminals
Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
Microsoft
Sunday, July 05, 2009 2:14:54 PMPage 5 © 2005 Mitchell Repair Information Company, LLC.

Fig. 3: Identifying Alternator Terminals (1992 B2200, B2600i & MPV)
Courtesy of MAZDA MOTORS CORP.

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
Microsoft
Sunday, July 05, 2009 2:14:54 PMPage 6 © 2005 Mitchell Repair Information Company, LLC.

Fig. 4: Identifying Alternator Terminals (1992 All Other Models)
Courtesy of MAZDA MOTORS CORP.
2. If output amperage is not equal to or more than amount specified in ALTERNATOR OUTPUT table,
repair or replace alternator as necessary.
3. Turn off all accessories and release brake pedal. With engine operating at 2500-3000 RPM, measure
output amperage. If output amperage is not at least 5 amps, repair or replace alternator as necessary.
4. With engine operating at 2500-3000 RPM, measure voltage between terminal "S" and ground. If reading
is not 14.1-14.7 volts, repair or replace alternator as necessar
y.

1991 Mazda MX-5 Miata
ALTERNATOR & REGULATOR 1990-92 ELECTRICAL Alternators & Regulators - Mitsubishi
Microsoft
Sunday, July 05, 2009 2:14:54 PMPage 7 © 2005 Mitchell Repair Information Company, LLC.