Voltage Regulator Testing
Set your voltmeter to 12VDC and connect the negative lead to the BLACK ground wire at the regulator as shown at in the
diagram at right.
With the ignition turned OFF, check voltage on the RED (power), Secondary RED on Terminal #12 (voltage sense)
BLUE (field) and BROWN (ignition) wires in the regula-
tor plug.
Voltages should be as follow:
•
RED wire equal to battery voltage
•
Terminal #12 RED wire equal to battery voltage
•
BLUE wire zero volts
•
BROWN wire zero volts
With the ignition in the ON position (engine not run-
ning), check voltage on the RED (power), Secondary
RED on Terminal #12 (voltage sense) BLUE (field) and
BROWN (ignition) wires in the regulator plug:
• RED wire equal to battery voltage
• Terminal #12 RED wire equal to battery voltage
• BLUE wire between 4V and 11V
• BROWN wire equal to battery voltage
PLEASE NOTE: In systems where the ignition (BROWN) wire is supplied power via an oil pressure switch, jump directly
from test #1 to test #3.
With the ignition in the ON position (with engine running at 1,400 rpm fastidle), check voltage on the RED (power),
Secondary RED on Terminal #13 (voltage sense) BLUE (field) and BROWN (ignition) wires in the regulator plug. Volt-
ages should be as follow:
• RED wire equal to battery voltage
• Terminal #12 RED wire equal to battery voltage
• BLUE wire between 4V and 11V
• BROWN wire equal to battery voltage
If voltage is not present on the RED, the BROWN and the Positive Battery Sense Wire, the regulator will not work. If volt-
age is as expected at the RED the BROWN and Positive Battery Sense wire, and there is zero, or an unexpected voltage
reading at the BLUE wire, contact our technical support staff at (360) 435-6100, or e-mail us at [email protected].
If all voltages at the regulator meet expectations, yet the alternator is not producing charging current, test the alternator.
The following tests are recommended for determining alternator functionality.
Alternator Testing
TEST #1The following test is used to isolate the alternator and determine if the failure is a result of the alternator. Once
again, testing at either the alternator or regulator is only effective if the wiring, fusing and batteries have been determined
to be in correct working order. The alternator and regulator can be tested for function by determining if a magnetic field
exists at the alternator’s pulley shaft or rear bearing. To test:
With the ignition in the OFF position, place the tip of a steel screwdriver near the nut on the pulley shaft or near the rear
bearing of the alternator. There should be no evidence of a magnetic field pulling the screwdriver toward the alternator.
(A slight amount of magnetism may be present, due to residual voltage in the alternator.
Engage the ignition, without starting the engine, to activate the voltage regulator. If an oil pressure switch is used, a
jumper between the RED and BROWN wires in the Ford-style plug will activate the regulator.
After allowing time for the regulator’s start-up delay, place the head of a steel screwdriver near the nut on the pul-
leyshaft or near the rear bearing of the alternator. There should be substantial magnetic pull. If a magnetic field is
present, the voltage regulator, alternator brushes and rotor are likely to be working properly.
1.
2.
3.
1.
2.
3.
- 14 -
