C.E. Niehoff & Co. C629 Troubleshooting Guides - Manual (Page 3)

Page 3 TG72A
Figure 4—Alternator Schematic Diagram
Section B: On-Vehicle Troubleshooting
BR
R
G
R
BR
A2-216 Regulator Troubleshooting
A2-216 regulator is either attached directly to the
outside of alternator.
Main diagnostic feature is a green lens LED located on
the front of the regulator. LED indicates whether regula-
tor has been energized. See Table 2 for LED indication
and status.
Regulators with OVCO (overvoltage cutout) will trip at
vehicle electrical system voltages above 32 volts that
exist longer than 3 seconds. OVCO feature detects high
voltage and reacts by signaling the alternator field
circuit to open. This turns off alternator. Restarting
engine resets OVCO circuit. Regulator regains control
of alternator output voltage.
TABLE 2 — A2-216 Regulator
LED Indications and Status
INDICATION STATUS
ON steady Normal regulator operation.
Alternator is producing output.
FLASHING Regulator is receiving energize
signal. LED will fl ash until
alternator produces output.
OFF Regulator is not receiving energize
signal or OVCO has tripped.