C.E. Niehoff & Co. N1617/N3264/N2013 Troubleshooting Guides - Manual (Page 5)

Page 5 TG82A
Section B: On-vehicle Troubleshooting
(CONT’D)
Chart 2: No Alternator Output – Test Charging Circuit
• TEST MEASUREMENTS ARE TAKEN ON HARNESS CONNECTOR AT ALTERNATOR. TEST MEASUREMENT AT
AN EXTENDED HARNESS PLUG MAY AFFECT RESULTS.
• REMOTE-MOUNTED REGULATORS: CHECK CONDITION OF FUSES IN EXTENDED WIRING HARNESS AND
PIN-TO-PIN CONTINUITY BEFORE TROUBLESHOOTING.
• BEFORE STARTING DIAGNOSTIC SEQUENCE, VERIFY THE FOLLOWING AND REPAIR/REPLACE IF NOT
TO SPEC:
—BATTERIES FOR STATE-OF-CHARGE (24.5-25.5 V), CONDITION, AND SECURE CONNECTIONS
—MASTER BATTERY SWITCH FOR FUNCTION
MASTER BATTERY SWITCH ON, KEY ON, ENGINE ON: Test for battery voltage at B+ terminal on alternator ADE
to ground. Disconnect vehicle wiring harness at regulator J2 connector and test for battery voltage at socket H on
vehicle harness plug (see Figure 8) to ground. Does battery voltage exist at both locations?
Yes No
RECONNECT VEHICLE WIRING HARNESS TO
REGULATOR J2 CONNECTOR.
ENGINE OFF: Disconnect 6-socket alternator-to-regulator
harness plug at alternator J1 connector.
Repair vehicle wiring as necessary. Run engine
and re-test charging circuit. Is charging system
performing properly?
System is operative.
No Yes
Figure 8 — Vehicle-to-regulator J2 18-socket Harness Plug
Disconnected at Regulator
VEHICLE-TO-REGULATOR J2 HARNESS PLUG SOCKET CONNECTIONS
A  J1939 +
B  J1939 −
C  J1939 Shield
D  Signal −
E  Battery Box Temp Sense
F  Battery Pack 1 Volt Sense
G  Battery Pack 2 Volt Sense
L, R, S, T, U Not Used
M, N, P Reserved
H  Energize
J  Regulator Status
K  Alternator Phase (AC)
If you have questions about your alternator or any of these test procedures, or if you need to locate a Factory Authorized Service Dealer, please contact us at:
C. E. Niehoff & Co.• 2021 Lee Street • Evanston, IL 60202 USA
TEL: 800.643.4633 USA and Canada • TEL: 847.866.6030 outside USA and Canada • FAX: 847.492.1242
E-mail us at [email protected]
Figure 7 — Alternator J 1 6-socket Connector
(ADE)
ALTERNATOR J 1
SOCKET CONNECTIONS
A  F–
B  AC
C  B–
D  B+
E  Alt Temp Sense
F  F+
A
B
C
D E
F
MASTER BATTERY SWITCH ON, KEY OFF, ENGINE OFF: Readings of all five tests must pass.
1. Battery voltage test: Connect DMM red lead to socket D on alternator J1 6-socket connector (see Figure 7).
Connect DMM black lead to socket C on same connector. Battery voltage should exist.
2. Field coil resistance test: Set DMM to ohms test. Field resistance between sockets F and A on alternator J1
6-socket connector should measure nominal 1.0-1.5 ± 0.2 ohms. Field coil is defective if reading is less than 0.5
ohms or greater than 3 ohms.
3. Significant magnetism test:
a. Securely connect one jumper wire between socket F on alternator J1 6-socket connector and B+ terminal on
alternator ADE.
b. Insert one end of second jumper wire in socket A on alternator J1 6-socket connector. Momentarily (1 sec.)
touch other end of second jumper wire to alternator B– terminal. Spark will occur at B– terminal. Touch steel
tool to shaft to detect significant magnetism.
c. Remove both jumper wires.
4. Alternator temperature sensor circuit test: Set DMM to ohms test. Sensor resistance between socket E on alterna-
tor J1 6-socket connector and B– terminal on alternator should measure 80-130K ohms at 70ºF (20ºC). Note: If
ambient temperature is higher, resistance will measure less than listed and vice versa.
5. Phase supply test: Set DMM to diode test. Connect DMM black lead to socket B on alternator J1 6-socket connector.
Connect red lead to alternator B+ terminal on ADE. DMM should read blocking in this direction. Then reverse
leads. DMM should read flow in this direction. Repeat for socket B and B– terminal. Tests should read flow in
one direction and blocking in the other direction.
Yes No
Alternator is defective. Regulator is defective.