C.E. Niehoff & Co. C622 Troubleshooting Guides User Manual
Page 7
Page 7
TG0011A
Test for battery voltage at alternator 28 V B+ terminal. Does battery voltage
exist?
Yes
No
Repair vehicle wiring as necessary. Continue test.
Vehicle charging circuit test is complete. Remove
jumper wire used in testing. Run engine and re-test
charging circuit for operation.
Chart 3 – No Alternator Output – Test Charging Circuit
Jumper 28 V B+ terminal on alternator to E terminal on regulator. Touch shaft with steel tool to detect
significant magnetism. Is shaft magnetized?
Yes
No
Go to energize switch on engine in E circuit. Test for
battery voltage going into energize switch from battery.
Does battery voltage exist?
Yes
No
Make sure jumper wire from alternator 28 V B+ termi-
nal to regulator E terminal is still attached.
Test for battery voltage at energize switch E terminal
connection. Does battery voltage exist at energize
switch?
E circuit from regulator to
energize switch is good.
Energize switch is defec-
tive.
STATIC TEST – ENGINE OFF, BATTERY SWITCH ON, KEY ON
Repair vehicle circuit to
energize switch. Continue test.
Yes
No
Repair vehicle circuit
from E terminal on
regulator to energize
switch on engine.
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
Disconnect jumper wire. Connect DMM red
lead to socket J in alternator-to-regulator
harness plug. Connect black lead to socket H in
same plug. Does battery voltage exist?
Yes
Alternator is
defective.
No
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
Regulator is
defective.
T
T
T
T
T
T
T
T
T
T
Section 3: Advanced Troubleshooting
Yes
Connect jumper wire from socket S in alter-
nator-to-regulator harness plug to 28 V B–
terminal on alternator. Spark will occur.
Touch shaft with steel tool to detect signifi-
cant magnetism. Is shaft magnetized?
No
T
T
T
T
T
Figure 5 – Alternator-to-Regulator Harness Plug
SOCKET CONNECTIONS
Pin G, F, E
84 V Phase
Pin R, Q, P
84 V SCR Gate
Pin D
84 V NEG
Pin C
84 V POS
Pin S
F –
Pin J
28 V B+
Pin H
28 V B –
Pin B, A, K
28 V Phase
Pin M, L, T
28 V SCR Gate
Alternator is
defective.