Subaru LEGACY 2003 Service Manual page 20

STARTING/CHARGING SYSTEMS
E: INSPECTION
1. DIODE
CAUTION:
Never use a mega tester (measuring use for
high voltage) or any other similar measure for
this test; otherwise, the diodes may be dam-
aged.
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.
(A) Diode lead
(B) Heat sink (Positive side)
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 )
(A) Diode lead
(B) Heat sink (Negative side)
GENERATOR
SC-00042
( B )
SC-00043
SC(H4SO)-18
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. 1.8 — 2.2 Ω Ω Ω 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.
SC-00044
SC-00045