C.E. Niehoff & Co. C714 Troubleshooting Guides - Manual (Page 4)

Page 4
TG54B
Section C: Advanced Troubleshooting
Figure 3 – Alternator-to-Regulator Harness Plug
PIN CONNECTIONS
Pin A F–
Pin B Phase
Pin C B–
Pin D B+
Pin E D+
Pin F F+
Chart 1 – No Output
Alternator is defective.


Connect B+ battery cable to alternator. Turn on battery switch.
Install a jumper from pin F in harness plug to B+ terminal on
alternator. Momentarily (1 sec.) jumper pin A in harness plug to
alternator B– terminal. Touch shaft with steel tool to detect sig-
nificant magnetism. Is shaft magnetized?
Yes No


Alternator is defective.
Turn off battery switch. Disconnect B+ battery cable at alterna-
tor. Set DMM to diode test. Connect black lead of DMM to pin E
in harness plug. Connect red lead to B+ terminal on alternator.
DMM should read OL. Reverse leads. DMM should also read OL.
Yes No
Alternator is defective.
 
Go to Chart 2, page 5.
With engine running, does battery voltage exist at alternator B+ terminal and regulator IGN terminal?
Yes No
Repair vehicle harness circuit to IGN terminal on
regulator or B+ terminal on alternator.


With engine off: Unplug alternator-to-regulator harness. Connect DMM across pin C and pin D in harness
plug. Does battery voltage exist?
Yes No
When conducting this step, ensure that the probes do not touch other pins, as an arc may damage
the wiring in the harness.
CAUTION