Subaru 2002 IMPREZA Service Manual page 427

2) Checking negative diode
Check for continuity between the negative side
heat sink and diode lead. The negative diode is in
good condition if resistance is 1 Ω or less only in the
direction from the heat sink to diode lead.
(A) Diode lead
(B) Heat sink (Negative side)
2. ROTOR
1) Slip ring surface
Inspect the slip rings for contamination or any
roughness of the sliding surface. Repair the slip
ring surface using a lathe or sand paper.
2) Slip ring outer diameter
Measure the slip ring outer diameter. If the 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 the resistance between slip rings using cir-
cuit tester.
If the resistance is not within specification, replace
the rotor assembly.
Specified resistance:
Approx. 2.7 — 3.2 Ω Ω Ω Ω
GENERATOR
4) Insulation test
Check the continuity between slip ring and rotor
core or shaft. If resistance is 1 Ω or less, the rotor
coil is grounded, and so replace the rotor assem-
bly.
S6M0407A
5) Ball bearing (rear side)
(1) Check the rear ball bearing. Replace if it is
noisy or if the rotor does not turn smoothly.
(2) The rear bearing can be removed by using
common bearing puller.
3. STATOR
1) Continuity test
Inspect the stator coil for continuity between each
end of the lead wires. If resistance is 1 M Ω or
more, the lead wire is broken, and so replace the
stator assembly.
G6M0075
SC-17
STARTING/CHARGING SYSTEMS
(A) Stator
G6M0076
G6M0077
G6M0078A