Rotor (Field) Winding Internal Short Test; Rotor (Raid) Winding Open Test; Stator Windings Short-To-Ground Test - Jeep J-10 Series 1982 Technical & Service Manual

Perform the test with an ohmmeter set for the xl scale
or with a 110-volt test lamp.
Touch one test lead probe to one slip ring and the
other test lead probe to the other slip ring (fig. 1E-5).
The ohmmeter should indicate 2.2 to 3.0 ohms or test
lamp should light.
Test Results
If the ohmmeter indicates infinite resistance or the
test lamp fails to light, the rotor winding is open.
Rotor (Field) Winding Internal Short Test
To perform this test, remove the front housing and
rotor from the stator and rear housing assembly. Refer
to Alternator Overhaul for procedure. This test is per
formed with a 12-volt battery and an ammeter.
OHMMETER
70156
Rg. 1E-5 Rotor (Raid) Winding Open Test
Connect battery and ammeter in series with the slip
rings (fig. 1E-6). The field current at 12 volts applied at
80°F (27°C) should be between 4.0 and 5.0 amps.
Test Results
Current flow exceeding 5.0 amps indicates a shorted
winding.
NOTE: The winding resistance and ammeter in
dication will vary slightly with winding temperature
changes. A current flow that is less than the specified
value indicates excessive winding resistance. An alter
nate test method is to determine the resistance of the
field winding by connecting an ohmmeter to the two slip
rings. If the resistance is less than 2.2 ohms at 80°F
(27°C), the winding is shorted. If the resistance is more
than 3.0 ohms at 80°F (27°C), the winding has excessive
resistance.
Stator Windings Short-to-Ground Test
To perform this test, separate the rear housing and
stator from the rotor and front housing assembly. Dis-
CHARGING SYSTEM 1E-5
12 VOLT BATTERY
70157
Fig. 1E-6 Rotor (Field) Winding Internal Short Test
connect the stator windings from the rectifier terminals.
Refer to Alternator Overhaul for procedure. The test is
performed with an ohmmeter set for the xlOOO scale or
with a 110-volt test lamp.
Touch one test lead probe to the bare metal surface of
the stator core and the other test lead probe to the end of
one stator winding (1E-7). Because all three stator wind
ings are soldered together, it is not necessary to test
each winding. The ohmmeter should indicate infinite
resistance (no pointer movement) or test lamp should
not light.
Test Results
If the ohmmeter indicates other than an infinite re
sistance or test lamp lights, the stator windings are
shorted to the core and must be replaced.
OHMMETER
7015A
Fig. 1E-7 Ststor Windings Short-to-Ground Test