Stator Short-To-Ground Test; Stator Continuity Test; Stator Internal Short Circuit Test; Diode Trio Short Circuit Test - Jeep 1979 CJ-5 Technical & Service Manual

1E-8 CHARGING SYSTEM
Test Results
Any ammeter reading above 4.6 amps indicates
shorted windings.
N O T E : The winding resistance and ammeter readings
will vary slightly with winding temperature changes. A
reading below the specified value indicates excessive
resistance. An alternate method is to check the resist-
ance of the field by connecting an ohmmeter to the two
slip rings. If the resistance reading is below 2.6 ohms at
80°F, the winding is shorted. If resistance is above 3.0
ohms at 80°F, the winding has excessive resistance.
Stator Short-to-Ground Tost
To perform this test, remove stator and rear housing
assembly from rotor and front housing assembly. Re-
move stator leads from rectifier terminals. Refer to Dis-
assembly for procedures. The test is performed with an
ohmmeter set to the 1000 scale or with a 110-volt test
lamp.
Touch one test lead to bare metal surface of stator
core and other test lead to end of one stator lead (1E-7).
Because all three stator leads are soldered together, it is
not necessary to test each lead. Ohmmeter should in-
dicate infinity (no needle movement) or test lamp should
not light.
Test Results
If ohmmeter indicates other than infinity or test lamp
lights, stator is grounded and must be replaced.
OHMMETER
7 0 1 5 8
Fig. 1E-7 Stator Short-to-Ground Test
Stator Continuity Tost
To perform this test, remove stator and rear housing
assembly from the rotor and front housing assembly.
Refer to Disassembly for procedure. An ohmmeter set to
the 1 scale is used to perform the tests.
Touch ohmmeter leads to two stator leads and note
reading (fig. 1E-8). Test all stator leads in this manner.
Equal readings should be obtained for each pair.
Test Results
An infinity reading (no needle movement) indicates
an open winding. Check the neutral junction splice for a
poor solder connection. Resolder the connection even
though it looks good. Recheck continuity. If an open still
exists, replace stator.
A reading of more than 1 ohm indicates a bad solder
joint. Check the neutral junction splice.
O H M M E T E R
Fig. 1E-8 Stator Continuity Test
Stator Internal Short Circuit Test
An internal short (for instance, between adjacent
windings) is difficult to locate without laboratory test
equipment. If all other electrical checks are normal and
alternator fails to supply rated output, shorted stator
windings are indicated.
Oiode Trio Short Circuit Test
The diode trio is tested in two ways, installed in the
rear housing and removed from the rear housing.
N O T E : Do not use high voltage, such as 110-volt test
lamp, to check the diode trio.
Test with Diode Trio Installed
(1) Before removing diode trio, connect an ohm-
meter, using lowest range scale, from brush lead clip to
rear housing (fig. 1E-9).
(2) Reverse lead connections. If both readings are
zero, check for grounded brush lead clip caused by omis-
sion of insulating washer, omission of insulating sleeve
over screw, or damaged insulation (fig. 1E-14),
(3) Remove screw to inspect sleeve. If screw assem-
bly is correct and both ohmmeter readings are same,
replace voltage regulator.