C.E. Niehoff & Co. N3012-N3210/N3107-N3121/N3237-N3211 Reg Test Procedures - Manual

Page 1
TG66B
N3012/N3210, N3107/N3121, N3237/N3211
Regulator General Test Procedures
General Alternator Test Procedure
1. Inspect charging system wiring.
a. Ensure all positive and negative battery
cables are free of corrosion and dirt and
tightened properly.
b. Check that all battery terminal stack
sequences meet manufacturer’s specifica-
tions. If there are two positive output
terminals on the alternator, there must be
a heavy gauge jumper wire between the two
output studs and also one between the
ground terminals of both alternator
housings.
c. Make sure drive belt and tensioner are in
good condition and to vehicle specification.
2. With battery switch on and ignition switch off,
measure voltage on alternator positive output
terminal(s). Reading should be 23.0-26.0 volts.
If not, make sure battery switch is on and
repair battery wiring if necessary. Voltage on
ignition terminal on regulator should be near
zero.
3. Start engine. Alternator RPM at idle should be
at least 1500 RPM.
a. Measure voltage at ignition terminal on
regulator. Reading should be 24.0-29.0
volts. If not, repair ignition wiring.
b. Measure voltage at alternator positive
output terminal(s). Reading should be
27.0-29.0 volts.
c. Apply inductive ammeter on alternator
main positive output stud. Meter should
read several amps, dependent on vehicle
electrical loads and battery state of charge.
If voltages measured in steps a and b are less
than listed and ammeter reads zero in step c,
alternator or regulator may need to be replaced.
Test regulator as shown on pages 2-4 for
appropriate regulator or apply new regulator
and repeat test. If test fails again, assume
alternator is faulty and refer to specific alterna-
tor troubleshooting guide for corrective action.
If voltage measured in steps a and b are less
than listed and ammeter reads high amper-
age in step c, alternator may be overloaded.
Remove electrical loads and charge or replace
batteries. Repeat test. If voltage is still low and
electrical load is within alternator output curve
specification, alternator/regulator may need to
be replaced. Test regulator as shown on pages
2-4 for appropriate regulator or apply new
regulator and repeat test. If test fails again,
assume alternator is faulty and refer to specific
alternator troubleshooting guide for corrective
action.
N3012/N3210 Regulator Test Setup Diagram ................................ 2
N3107/N3121 Regulator Test Setup Diagram ............................... 3
N3237/N3211 Regulator Test Setup Diagram ............................... 4