C.E. Niehoff & Co. C711/C712 Troubleshooting Guides User Manual

Page 5

Page 5

TG0009A

C. E. Niehoff & Co.

BRUSHLESS ALTERNATORS

Test for battery voltage at B+ terminal on alternator to ground, then at F+ terminal on alterna-
tor to ground. Does battery voltage exist?

Yes

Repair vehicle wiring as necessary. Continue test.

Vehicle charging circuit test is complete.
Remove jumper wire. Run engine and
re-test charging circuit for operation.

Chart 2 – No Alternator Output – Ener

Ener

Energize Switch

gize Switch

gize Switch – Test Charging Circuit

Jumper B+ terminal on alternator to E terminal
on alternator. Touch shaft with steel tool to de-
tect significant magnetism. Is shaft magnetized?

Yes

Go to energize switch on engine in E circuit.
Test for battery voltage going into energize switch
from battery. Does battery voltage exist?

Yes

Make sure jumper wire from alternator B+
terminal to alternator 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 alterna-
tor to energize switch is
good. Energize switch is
defective.

STATIC TEST ENGINE OFF, BATTERY SWITCH ON, KEY ON

Repair vehicle circuit to
energize switch. Continue test.

Yes

Repair vehicle circuit
from E teminal on
alternator to energize
switch on engine.

Section 3: Advanced Troubleshooting

(CONTD)

Figure 3 Alternator-to-Regulator Harness Plug

SOCKET CONNECTIONS

Socket A B

Socket B Energize

Socket C Field

Socket D Not Used

Socket E B+

Unplug alternator-to-regulator harness. Plug
CEN Regulator Bypass Adapter A10-129 into
harness plug and touch black lead to ground
on alternator case. (If no Adapter is available,
connect jumper wire from socket C on the
harness to ground). Spark will occur at
ground. Touch steel tool to shaft to detect
significant magnetism. Is shaft magnetized?

Disconnect Regulator Bypass Adapter or jumper wire.
Connect DMM red lead to socket E in alternator-to-
regulator plug. Connect black lead to socket A in same
plug. Does battery voltage exist?

Regulator is
defective.

Yes

Check wiring and connections to
alternator.

Run engine and re-test charging
circuit for operation.

Yes

Alternator
is defective.