Mazda MX-5 Miata (1997+). Manual — part 37

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

1997 Mazda MX-5 Miata

GENERATOR & REGULATOR 1997 STARTING & CHARGING SYSTEMS Mazda - Generators & Regulators

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

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

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