1997 MAZDA MX-5 Factory Repair Manual

Fig. 7: Measuring Brush Wear
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
Microsoft
Sunday, July 05, 2009 1:53:16 PMPage 9 © 2005 Mitchell Repair Information Company, LLC.

Fig. 8: Checking Rotor For Shorts
Courtesy of MAZDA MOTORS CORP.
Fig. 9: Checking Rotor Resistance

Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
Microsoft
Sunday, July 05, 2009 1:53:16 PMPage 10 © 2005 Mitchell Repair Information Company, LLC.

OVERHAUL
DISASSEMBLY
1. Place a 200-watt soldering iron against rear bearing for 3-4 minutes to heat rear cover to 122-140°F (50-
60°C). Carefully separate front case and rotor from rear cover and stator. See Fig. 10
thru Fig. 15 and
Fig. 17
.
2. Position rotor in vise. Remove pulley. Disassemble pulley, rotor and front case. Remove front bearing
from front case. Using a bearing puller, remove rear bearing.
3. Remove "B" terminal nut and bushing from rear cover. Remove screws from brush holder and rectifier.
Separate rear cover and stator. When unsoldering rectifier and stator leads, disconnect as quickly as
possible (5 seconds maximum) to avoid damage to rectifier. To remove brushes from holder, unsolder
pigtail from terminal.
REASSEMBLY
Brush Installation
1. Install brush and spring into holder. Allow brush to extend out of holder until wear limit line extends .08-
.16"(2-4 mm) beyond end of brush holder. See Fig. 16
. Solder pigtail onto brush holder.
2. Insert spring and brush into brush holder. Using a spring scale, pull brush into holder until end of brush
protrudes .08" (2.0 mm) from holder. See Fig. 10
thru Fig. 15 . Note reading on spring scale. Replace
spring if tension is not 5.6-15.5 ozs. (160-440 g).

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
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Sunday, July 05, 2009 1:53:16 PMPage 11 © 2005 Mitchell Repair Information Company, LLC.

Fig. 10: Heating Rear Bearing Housing
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
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Sunday, July 05, 2009 1:53:16 PMPage 12 © 2005 Mitchell Repair Information Company, LLC.

Fig. 11: Removing Rear Bearing
Courtesy of MAZDA MOTORS CORP.
Fig. 12: Unsoldering Rectifier From Regulator

Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
Microsoft
Sunday, July 05, 2009 1:53:16 PMPage 13 © 2005 Mitchell Repair Information Company, LLC.

Fig. 13: Replacing Brushes
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
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Sunday, July 05, 2009 1:53:16 PMPage 14 © 2005 Mitchell Repair Information Company, LLC.

Fig. 14: Measuring Brush Spring Tension
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
Microsoft
Sunday, July 05, 2009 1:53:16 PMPage 15 © 2005 Mitchell Repair Information Company, LLC.

Fig. 15: Inserting Wire To Retain Brushes For Reassembly
Courtesy of MAZDA MOTORS CORP.

1997 Mazda MX-5 Miata
GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators
Microsoft
Sunday, July 05, 2009 1:53:16 PMPage 16 © 2005 Mitchell Repair Information Company, LLC.