C.E. Niehoff & Co. N1313 Troubleshooting Guides - Manual (Page 3)

Page 3
TG16F
Section B: Basic Troubleshooting
Basic Troubleshooting
1. Inspect charging system components
Check connections at ground cables, positive
cables, and regulator harness. Repair or replace
any damaged component before troubleshooting.
2. Inspect connections of vehicle batteries
Connections must be clean and tight.
3. Determine battery type, voltage and state
of charge
Batteries must be all the same type for system
operation. If batteries are discharged, recharge or
replace batteries as necessary. Electrical system
cannot be properly tested unless batteries are
charged 95% or higher. See page 1 for details.
Nominal battery voltage for 28 V systems is 25.2
±0.2 V; for 14 V systems is 12.6 ±0.2 V. Less than
25 V or 12.4 V indicates no charge condition when
engine is running.
4. Connect meters to alternator
Connect red lead of DMM to alternator 28 V B+
terminal and black lead to alternator B– terminal.
Clamp inductive ammeter on 28 V B+ cable.
5. Operate vehicle
Observe charge voltage at batteries with engine
running (nom. 27-28 V or 13.5-14.0 V).
If charge voltage is above 32 V
for 28 V system or 16 V for 14 V
system, immediately shut down
system. Electrical system
damage may occur if charging
system is allowed to operate at
excessive voltage. Go to Table 1
at left.
If voltage is at or below regulator setpoint, let
charging system operate for several minutes to
normalize operating temperature.
6. Observe charge volts and amps in each circuit
Charge voltage should increase and charge amps
should decrease. If charge voltage does not
in- crease within ten minutes, continue to next step.
7. Batteries are considered fully charged if charge
voltage is at regulator setpoint and charge amps
remain at lowest value for 10 minutes.
8. If charging system is not performing properly,
go to Chart 1, page 5.
SYMPTOM ACTION
TABLE 1 – System Conditions
Check: loose drive belt; low battery
state of charge.
Check: current load on system is
greater than alternator
can produce.
Check: defective alternator or
regulator.
Check: wrong regulator.
Check: defective regulator.
Check: alternator.
Check: presence of energize signal.
Check: battery voltage at alternator
output terminal.
Check: defective alternator or
regulator.
Go to Chart 2, page 6.
Low Voltage Output
High Voltage Output
No Voltage Output
Preliminary Check-out
Check symptoms in Table 1 and correct if necessary.
Tools and Equipment for Job
• Digital Multimeter (DMM)
• Ammeter (digital, inductive)
• Jumper wires
Identification Record
List the following for proper troubleshooting:
Alternator model number _________________________
Regulator model number ________________________
Setpoint listed on regulator _______________________
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No 14 V Output
CAUTION