C.E. Niehoff & Co. C626 Troubleshooting Guides - Manual (Page 4)

Page 4 TG67B
Section C: Advanced Troubleshooting
A2-337 Regulator
Description and Operation
A2-337 regulator is attached directly to the outside of
alternator. A9-4011 temperature sense lead may or may
not be used with this regulator. See below.
Main diagnostic feature of the regulator is a tricolored
LED next to the harness receptacle on regulator. LED
works like a voltmeter, measuring charging voltage. See
Table 2 for diagnostic features and LED explanations.
When the A9-4011 temperature sense lead is not in use,
the regulator will operate at 27.5 V.
When A9-4011 temperature sense lead is in use, the
lead senses the ambient temperature within the battery
box and regulator will adjust charge voltage based on
battery temperature—the higher the battery tempera-
ture, the lower the charge voltage.
LED COLOR STATUS
TABLE 2 – A2-337 Regulator Diagnostics
Alternator and regulator operating normally.
Regulator is in soft start mode. GREEN Solid
Flashing
Low system voltage — Electrical load exceeds
alternator rating at present rotor speed.
ACTION
No action required.
Wait 10 seconds until alternator achieves full
rotation.
When loads decrease or speed increases, LED
should be solid GREEN. If not, check drive belt
and charging system connections. AMBER Solid
High system voltage. May occur during normal load switching. RED Solid
Alternator fault — No output. Flashing Replace alternator.