C.E. Niehoff & Co. N1610 Troubleshooting Guides - Manual (Page 3)

Page 3 TG61B
Section B: Basic Troubleshooting
Basic Troubleshooting
1. Inspect charging system components for damage
Check connections at B– cables, B+ cables,
B+ interconnect cable, B– interconnect cable,
and alternator-to-regulator harness. Repair or
replace any damaged component before trouble-
shooting.
2. Inspect all vehicle battery connections
Connections must be clean and tight.
3. 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. In addition, open circuit voltages
must be within ± 0.2 V.
4. Connect meters to alternator
Connect red lead of DMM to alternator anti-drive
end B+ terminal and black lead to alternator
anti-drive end B– terminal. Clamp inductive
ammeter on anti-drive end B+ cable.
5. Operate vehicle
Observe charge voltage at batteries with engine
running (nom. 27-28 V or 13.5-14.0 V).
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 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.
Go to Chart 2, page 6.
Low Voltage Output
High Voltage Output
No 28 V 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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CAUTION
No 14 V Output
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
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.