Subaru Impreza 2004 - Page 301

SC(H4SO)-17
STARTING/CHARGING SYSTEMS
Generator
1) Checking positive diode
Check for continuity between the diode lead and
positive side heat sink. The positive diode is in
good condition if resistance is 1 Ω or less only in the
direction from the diode lead to heat sink.
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.
2. ROTOR
1) Slip ring surface
Inspect the slip rings for contamination or any
roughness on 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 the 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 the specified range,
replace the rotor assembly.
Specified resistance:
Approx. 1.8 — 2.2
Ω
ΩΩ
Ω
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.
5) Ball bearing (rear side)
Check the rear ball bearing. Replace if it is noisy or
if the rotor does not turn smoothly.
3. STATOR
1) Continuity test
Inspect the stator coil for continuity between each
end of the lead wires. If resistance is 1 MΩ or more,
the lead wire is broken, and so replace the stator
assembly.
(A) Diode lead
(B) Heat sink (positive side)
(A) Diode lead
(B) Heat sink (negative side)
( A )
( B )
SC-00042
SC-00043
( A )
( B )
(A) Stator
SC-00044
SC-00045
( A )
SC-00047