C.E. Niehoff & Co. C520 Troubleshooting Guides - Manual (Page 5)

Page 5
TG0048A
Section 4: Advanced Troubleshooting
A2-215 and A2-326 Regulators
DESCRIPTION AND OPERATION
A2-215 regulator is attached directly to the outside of
the alternator. A2-326 regulator is remotely mounted
from extended wiring harnesses.
Main diagnostic feature of
A2-215 regulator is green
lens LED. The LED indicates field coil performance.
See Table 5 for diagnostic features and LED explana-
tions.
Main diagnostic feature of
A2-326 regulator consists
of a tricolored (green, amber, red) LED located on the
side of the regulator. The LED works like a voltmeter,
measuring charging voltage. See Table 6 for diagnostic
features and LED explanations.
LED COLOR STATUS
TABLE 6 – A2-326 Regulator Diagnostics
Alternator and regulator operating normally.
GREEN Flashing*
If alternator is rotating: System voltage lower
than setpoint – electrical load exceeds alter-
nator rating at present rotor speed.
ACTION
No action required.
Check drive belt, increase RPM. AMBER Flashing *
System voltage higher than setpoint. May occur during normal load switching.
Overvoltage condition. Attempt reset. System diag-
nosis required.
RED Flashing*
Steady OVCO tripped.
CLEAR LED off Check for system voltage at IGN terminal on
regulator. If OK, replace regulator. If not OK,
check vehicle wiring and ignition circuit.
Energize signal present, alternator not rotat-
ing or alternator speed too low for cut-in.
Energize circuit fault.
When loads decrease or speed increases, LED
should flash GREEN. If not, check drive belt
and charging system connections.
TROUBLESHOOTING A2-326 REGULATOR
Shut down vehicle and restart engine. If alternator
functions normally after restart, a “no output condi-
tion” was normal response of voltage regulator to
overvoltage condition. Inspect condition of electrical
system.
If you have reset alternator once, and electrical system
returns to normal charge voltage condition, there may
have been a one time, overvoltage spike that caused
OVCO circuit to trip.
If OVCO circuit repeats cutout a second time in short
succession and shuts off alternator F+ circuit, try
third restart. If OVCO circuit repeats cutout a third
time, check color of LED while engine is running.
* Flashing occurs twice per second.
LED CONDITION STATUS
TABLE 5 – A2-215 Regulator Diagnostics
Field on full. GREEN On steady
ACTION
No action required.
Check drive belt, moderate RPM if necessary. GREEN Flashing
CLEAR LED off Check condition of field circuit.
Speed of LED flashing determines alternator
output.
Field off.