Impreza 2.5 RS Coupe AWD F4-2.5L SOHC (2001)
Alternator: Testing and Inspection
1. ROTOR
1. Slip ring surface
Inspect slip rings for contamination or any roughness of the sliding surface. Repair slip ring surface using a lathe or sand paper.
2. Slip ring outer diameter
Measure slip ring outer diameter. If slip ring is worn replace rotor assembly.
Slip ring outer diameter:
Standard : 22.7 mm (0.894 in)
Limit : 22.1 mm (0.870 in)
3. Continuity test
Check resistance between slip rings using circuit tester. If the resistance is not within specification, replace rotor assembly.
4. Insulation test
Check continuity between slip ring and rotor core or shaft. If continuity exists, the rotor coil is short-circuited, and so replace rotor assembly.
5. Ball bearing rear side)
1. Check rear ball bearing. Replace if it is noisy or if rotor does not turn smoothly.
2. The rear bearing can be removed by using common bearing puller.
2. STATOR