Alternator (Fa20): Inspection

Standard length: 22.5 mm {0.885 in}

Minimum length: 5.0 mm {0.196 in}

Fig 1: Measuring Brush Length

Courtesy of SUBARU OF AMERICA, INC.

If the brush length is less than the minimum, replace the brush.

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   1 - 2	Always	Below 1 Ω
   1 - 3
   2 - 3
   4 - 5
   4 - 6
   5 - 6

   Fig 2: Checking Generator Coil Assembly Resistance (Lead Wire)

   Courtesy of SUBARU OF AMERICA, INC.

   If the result is not as specified, replace the generator coil assembly.

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   Stator core - Lead wire	Always	10 kΩ or higher

   Fig 3: Checking Generator Coil Assembly Resistance (Stator Core - Lead Wire)

   Courtesy of SUBARU OF AMERICA, INC.

   If the result is not as specified, replace the generator coil assembly.

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   Slip ring - Slip ring	20°C (68°F)	2.0 to 2.4 Ω

   Fig 4: Checking Generator Rotor Assembly For Open

   Courtesy of SUBARU OF AMERICA, INC.

   If the result is not as specified, replace the generator rotor assembly.

1. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   Slip ring - Rotor core	Always	10 kΩ or higher

   Fig 5: Checking Generator Rotor Assembly For Ground

   Courtesy of SUBARU OF AMERICA, INC.

   If the result is not as specified, replace the generator rotor assembly.

1. Using a vernier caliper, measure the diameter of each slip ring.

   Standard diameter: 22.7 mm {0.893 in}

   Minimum diameter: 22.1 mm {0.870 in}

   If the diameter is less than the minimum, replace the generator rotor assembly.

   Fig 6: Checking Slip Ring Diameter

   Courtesy of SUBARU OF AMERICA, INC.

1. Measure the resistance according to the value(s) in the table below.
   Fig 7: Inspecting Generator Holder With Rectifier

   Courtesy of SUBARU OF AMERICA, INC.

   Standard Resistance

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   P1, P2, P3, P4, P5, P6 - B	P1, P2, P3, P4, P5, P6 (Tester positive) B (Tester negative)	Below 1 Ω
   	P1, P2, P3, P4, P5, P6 (Tester negative) B (Tester positive)	10 kΩ or higher
   P1, P2, P3, P4, P5, P6 - E	P1, P2, P3, P4, P5, P6 (Tester positive) E (Tester negative)	10 kΩ or higher
   	P1, P2, P3, P4, P5, P6 (Tester negative) E (Tester positive)	Below 1 Ω

   If the result is not as specified, replace the generator holder with rectifier.