C.E. Niehoff & Co. C619, C630, N1222, N1223, A1-607 Troubleshooting Guides

C.E. Niehoff & Co.

C630, C619, N1222, N1223, A1-607, A1-608

Alternator Troubleshooting Guide

Hazard Defi nitions

These terms are used to bring attention to presence of hazards of
various risk levels or to important information concerning product
life.
Indicates presence of hazards that

CAUTION

will or can cause minor personal
injury or property damage.

Indicates special instructions on

NOTICE

installation, operation or mainte­ nance that are important but not
related to personal injury hazards.

Table of Contents

Section A: Wiring Diagram .......................................2

Section B: Basic Troubleshooting .............................3

Section C: Advanced Troubleshooting ................ 4 – 6

Section D: Regulator Upgrade Guide ........................7

Battery Conditions

Until temperatures of electrical

NOTICE

system components stabilize, these
conditions may be observed during
cold-start voltage tests.

• Maintenance/Low Maintenance Battery
— Immediately after engine starts, system volts are
lower than regulator setpoint, amps are medium.
— 3–5 minutes into charge cycle, system volts
increase, amps decrease.
— 5–10 minutes into charge cycle, system volts
increase to, or near, regulator setpoint and amps
decrease to a minimum.
— Low maintenance battery has same characteristics
with slightly longer recharge times.

• Maintenance-free Battery
— Immediately after engine starts, system volts are
lower than regulator setpoint, low charging amps.
— Once charge cycle begins, low volts and low amps
are still present.
— After alternator energizes, voltage will increase
several tenths. Amps will increase gradually, then
quickly, to medium to high amps.
— F i n a l l y , v o l t s w i l l i n c r e a s e t o s e t p o i n t a n d a m p s w i l l
decrease.
The time it takes to reach optimum voltage and amper­age will vary with engine speed, load, and ambient
temperature.

• High-cycle Maintenance-free Battery
These batteries respond better than standard mainte­nance-free. Charge acceptance of these batteries may
display characteristics similar to maintenance batteries.

• AGM (Absorbed Glass Mat) Maintenance-free Batter y
These dry-cell batteries respond better than standard
maintenance-free. If battery state of charge drops to
75% or less, batteries should be recharged to 95% or
higher separately from the engine’s charging system to
avoid damaging charging system components and to
provide best overall performance. Charge acceptance of
these batteries may display
maintenance batteries.

characteristics similar to

Battery Charge Volt and Amp Values

Volt and amp levels fluctuate depending on the battery state
of charge. If batteries are in a state of discharge—as after
extended cranking time to start the engine—system volts
will measure lower than the regulator setpoint after the
engine is restarted and system amps will measure higher.
This is a normal condition for the charging system; the
greater the battery discharge level, the lower the system
volts and the higher the system amps. The volt and amp
readings will change as batteries recover and become fully
charged: system volts will increase to regulator setpoint
and system amps will decrease to low level (depending on
other loads).

• Low Amps: Minimum or lowest charging system amp
value required to maintain battery state of charge,
obtained when testing the charging system with a fully
charged battery and no other loads applied. This value
will vary with battery type.

• Medium Amps: System amps value which can cause
the battery temperature to rise above adequate charging
temperature within 4-8 hours of charge time. To pre­vent battery damage, the charge amps should be
reduced when battery temperature rises. Check battery
manufacturer’s recommendations for proper charge
amp rates.

• High Amps: System amps value which can cause
the battery temperature to rise above adequate charging
temperature within 2-3 hours of charge time. To pre­vent battery damage, the charge amps should be
reduced when battery temperature rises. Check battery
manufacturer’s recommendations for proper charge
amp rates.

• Battery Voltage: Steady-state voltage value as mea-
sured with battery in open circuit with no battery load.
This value relates to battery state of charge.

• Charge Voltage: Voltage value obtained when the
charging system is operating. This value will be higher
than battery voltage and must never exceed the regula­tor voltage setpoint.

• B+ Voltage: Voltage value obtained when measuring
voltage at battery positive terminal or alternator B+
terminal.

• Surface Charge: Higher than normal battery voltage
occurring when the battery is disconnected from
battery charger. The surface charge must be removed
to determine true battery voltage and state of charge.

• Significant Magnetism: Change in strength or inten-
sity of a magnetic field present in alternator rotor shaft
when the field coil is energized. The magnetic field
strength when the field coil is energized should feel
stronger than when the field is not energized.

• Voltage Droop or Sag: Normal condition occurring
when the load demand on alternator is greater than
rated alternator output at given rotor shaft RPM.

TG8B

Page 1

Section A: Wiring Diagrams

CEN C630/C619/N1222/N1223/A1-607/A1-608
Alternators Description and Operation

The C630 alternator (14 V, 350 A), C619 alternator
(14 V, 340 A), N1222/A1-608 alternators (14 V, 290 A)
and N1223/A1-607 alternators (14 V, 250 A) are inter­nally rectified. All windings and current-transmitting
components are non-moving, so there are no brushes or
slip rings to wear out. This unit is externally energized
through either an ignition switch or an energize switch
(commonly an oil pressure switch), which activates regu­lator. Field coil is then energized. Regulator maintains
alternator output voltage at regulated setting as vehicle
electrical loads are switched on and off. Alternator out­put current is self-limiting and will not exceed rated
capacity of alternator.

A2-121 regulator used with all units has a 15.5 V regula­tor setpoint available for battery isolator applications.

Electromagnetic interference (EMI) is suppressed with
internal filters to acceptable levels defined by the Society
of Automotive Engineers (SAE) specification J1113/41.
A2-121 regulator will not reduce EMI from sources such
as antennas, poor cable routing practice, or other elec­tronic devices that cause EMI. If EMI continues, consult
an electromagnetic compliance (EMC) specialist to
determine EMI source.

P3



P2

F+ Terminal

E or IGN

P1

B+ Terminal





B– Terminal

Figure 1 — Alternator with A2-121 Regulator

RECTIFIER

STATOR

STATOR

ALTERNATOR

or IGN

FIELD

B+

F+

P2
P3

B–

P1

E

G

BR

W

R

A
B
C

E

ENERGIZE
SWITCH

REGULATOR

BATTERY

LOAD

Page 2

Figure 2 — Alternator Wiring Diagram

TG8B

Section B: Basic Troubleshooting

Tools and Equipment for Job

• Digital Multimeter (DMM)

• Ammeter (digital, inductive)

• Jumper wires

• CEN Regulator Bypass Adapter A10-129

• 12 V test light

Identifi cation Record

List the following for proper troubleshooting:

Alternator model number _________________________



Regulator model number ________________________



Setpoints listed on regulator _____________________



Preliminary Check-out

Check symptoms in Table 1 and correct if necessary.

TABLE 1 – System Conditions

SYMPTOM ACTION

Low Voltage Output

High Voltage Output

No Voltage Output

Check: loose drive belt; low

battery state of charge.

Check: current load on system

is greater than alternator
can produce.

Check: defective wiring or poor

ground path; low regulator
setpoint.

Check: defective alternator

or regulator.

Check: wrong regulator.

Check: high regulator setpoint.

Check: defective regulator.

Check: alternator.

Check: broken drive belt.

Check: battery voltage at alternator

output terminal.

Check: defective alternator

or regulator.

Failure to check for the following

NOTICE

conditions will result in erroneous
test results in the troubleshooting
charts.

Basic Troubleshooting

1. Inspect charging system components for damage

Check connections at B– cable, B+ cable, and
regulator harness. Also check connections at
regulator terminal wiring from regulator to vehicle
components. Repair or replace any damaged
component before electrical troubleshooting.

2. Inspect vehicle battery connections

Connections must be clean and tight.

3. Check drive belt

Repair or replace as necessary.

4. Determine battery voltage and state of charge

If batteries are discharged, recharge or replace
batteries as necessary. Electrical system cannot be
properly tested unless batteries are charged 95% or
higher.

5. Determine if battery isolator is used in

charging circuit

Check vehicle wiring diagram. If so, you must

jumper isolator before troulbleshooting. See
Chart 1 on page 4 for deatils.

6. Connect meters to alternator

Connect red lead of DMM to alternator B+
terminal and black lead to alternator B– terminal.
Clamp inductive ammeter on B+ cable.

7. Operate vehicle

Observe charge voltage.
If charge voltage is above

16.5 volts, immediately shut
down system. Electrical
system damage may occur if
charging system is allowed to
operate at high voltage.
Go to Table 1.

If voltage is at or below regulator setpoint, let

charging system operate for several minutes to
normalize operating temperature.

8. Observe charge volts and amps

Charge voltage should increase and charge amps
should decrease. If charge voltage does not
increase within ten minutes, continue to next step.

9. Battery is considered fully charged if charge

voltage is at regulator setpoint and charge amps
remain at lowest value for 10 minutes.

10. If charging system is not performing properly,

CAUTION

go to Chart 1, page 4.

TG8B

Page 3

Section C: Advanced Troubleshooting

START HERE

Install temporary jumper between one battery terminal and alternator
terminal on isolator. Use minimum 12 AWG wire.

Do not operate charging system more than two

CAUTION

minutes with jumper installed. Charging system volt­age will be abnormally high and damage other components.

For “no voltage output” condition: • with energize switch, go to Chart 2, page 5.

• with ignition switch, go to Chart 3, page 6.



Is there a battery isolator in the system?

Yes





Chart 1 – System Circuit

No



Page 4

TG8B

Section C: Advanced Troubleshooting (CONT’D)

Chart 2 – No Alternator Output – Energize Switch – Test Charging Circuit

STATIC TEST – ENGINE OFF, BATTERY SWITCH ON, KEY ON

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

Yes



Jumper B+ terminal on alternator to E or IGN
terminal on alternator. Touch shaft with steel tool to
detect significant magnetism. Is shaft magnetized?

Yes

No



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

Yes

No



Repair vehicle circuit to
energize switch. Continue test.



Make sure jumper wire from alternator B+ termi­nal to alternator E or IGN terminal is still attached.

Test for battery voltage at energize switch E termi­nal connection. Does battery voltage exist
at energize switch?

Yes



Energize circuit from
alternator to energize
switch is good. Energize
switch is defective.

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



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



No





No





Repair vehicle wiring as necessary. Continue test.

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, con-



nect 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?

Yes

No



Alternator
is defective.



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?

Yes



Regulator is
defective.

SOCKET CONNECTIONS

Socket A B–
Socket B Energize
Socket C Field –
Socket D Not Used
Socket E B+

Figure 3 – Alternator-to-Regulator Harness Plug

Check wiring and connections to
alternator.

Run engine and re-test charging
circuit for operation.

No



TG8B

Page 5

Section C: Advanced Troubleshooting (CONT’D)

Chart 3 – No Alternator Output – Ignition Switch – Test Charging Circuit

STATIC TEST – ENGINE OFF, BATTERY SWITCH ON, KEY ON

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

Yes



Jumper B+ terminal on alternator to E or IGN
terminal on alternator. Touch shaft with steel tool
to detect significant magnetism. Is shaft magnetized?

Yes

No



Disconnect jumper. Apply 12 V test light to
alternator E or IGN terminal and ground.
Does light glow brightly?

Yes

No



Repair wiring or
ignition switch.



Run vehicle. Does charge voltage exist?

Yes



System
operating
normally.

Jumper B+ terminal on
alternator to E or IGN termi­nal on alternator. Does
charge voltage exist?

Yes

No



No

No







Repair vehicle wiring as necessary. Continue test.

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, con-



nect 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?

Yes

No



Alternator
is defective.



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.

No



Page 6



Repair wiring
or ignition
switch.



Contact CEN
Service
Department
for assistance.

SOCKET CONNECTIONS

Socket A B–
Socket B Energize
Socket C Field –
Socket D Not Used
Socket E B+

Figure 4 – Alternator-to-Regulator Harness Plug

TG8B

Section D: Regulator Upgrade Guide

OLD REGULATOR# NEW REGULATOR #

A2-119
A2-120 USE A2-121
A2-113
A2-707

If you have questions about your a lternator or a ny 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: [phone] USA and Canada • TEL: [phone] outside USA and Canada • FAX: [phone]

E-mail us at [e-mail]

TG8B

Page 7