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TG0060A
Section C: Advanced Troubleshooting
A2-334 and A2-335 Regulators
DESCRIPTION AND OPERATION
A2-334
regulator is mounted directly to the outside
of the alternator.
A2-335
regulator is mounted
remotely on the vehicle and connected to alternator
with extended wiring harnesses.
Main diagnostic feature of regulators consists of a
tricolored (green, amber, red) LED located on the
end of the regulator. The LED works like a voltmeter,
measuring charging voltage. See Table 2 for diagnos-
tic features and LED explanations.
LED COLOR
STATUS
TABLE 2 – Regulator Diagnostics
Alternator and regulator operating normally.
GREEN
Solid
System voltage is lower than setpoint—electrical
load exceeds alternator 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.
RED
Flashing
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 rotating
or alternator speed too low for cut-in.
Energize circuit fault.
When loads decrease or speed increases, LED
should be solid GREEN. If not, check drive belt
and charging system connections.
Solid
