TM 9-2320-280-34
6-5.2. 400 AMPERE DUAL VOLTAGE AL ERNATOR (12469057) TESTING AND REPAIR (Cont'd)
T
c. Static Testing
NOTE
Refer to disassembly for component removal, if necessary.
1.
Perform Stator Test:
NOTE
Steps (a) through (f) apply to test procedure for end housing.
Steps (a) through (e) apply to test procedure for front housing.
(a) Remove six nuts and phase leads from diodes in end housing.
(b) Set multimeter to X1 scale and zero multimeter.
(c) Connect multimeter leads between each phase leads P1-P2, P2-P3, and P1-P3. Multimeter
∞
should read less than 1 ohm. If multimeter reads infinity ( ), the stator is open; replace
(d) Set multimeter to X1 scale and zero multimeter.
(e) Connect multimeter leads between each phase lead, P1, P2, and P3 and ground terminal on
∞
outside of front housing. Multimeter should read infinity ( ). If multimeter reads zero, the
stator is grounded; replace alternator.,
(f) Repeat step (e) to check phase lead P4, P5, and P6.
2.
Perform Field Coil Test for End Housing Only:
(a) Remove two nuts and field coil leads (F+, F-) from diodes in end housing.
(b) Set multimeter to XI scale and zero multimeter.
(c) Connect multimeter leads to the two field leads and measure the resistance. Multimeter should
read less than 3 ohms. If multimeter reads more than 3 ohms, field coil is open; replace
(d) Set multimeter to X10K scale and zero multimeter.
(e) Connect one multimeter lead to a field lead and other to ground stud on front housing.
∞
Multimeter should read infinity ( ). If multimeter reads less than 100K ohms, field coil is
grounded. Replace alternator.
3.
Perform Positive Diode Test:
(a) Set multimeter to X100 scale and zero multimeter.
(b) Connect one ohmmeter lead to B+ output stud and other lead to each of six diode terminals S.
Multimeter should read either less than 600 ohms or infinity (∞ ) for all six diode terminals.
Reverse multimeter leads. Multimeter should read nearly alike for all six, but opposite first set
of readings. If readings are not opposite, diode rectifier assembly is open. Replace alternator.
4.
Perform Negative Diode Test:
(a) Set multimeter to X100 scale and zero multimeter.
(b) Connect one multimeter lead to ground terminal and other lead to each of six diode terminals S.
Multimeter should read either less than 600 ohms or infinity (∞ ) for all six diode terminals.
Reverse multimeter leads. Multimeter should read nearly alike for all six, but opposite first set
of readings. If readings are not opposite, diode rectifier assembly is open. Replace alternator.
6-44.20
Change 1
