If there is little or no magnetic pull at the pulley shaft or at the rear bearing, initiate the following test:
With the key off and the engine off, remove the large harness plug from the regulator.
Insert the end of a short length of electrical wire to the RED connector slot of
the regulator harness and the other end of the wire to the BLUE connector slot.
This bypasses the regulator and tests the alternator and the harness.
Using your steel screwdriver, inspect for a magnetic field as described above.
With your voltmeter, check for voltage on the blue wire at the alternator. If volt-
age does not exist, the harness may be at fault. If voltage does exist at the
harness, but no magnetism is present, the alternator is likely to be malfunc-
tioning.
If a magnetic field is present. Both harness and alternator brushes and rotor
appear to be working properly. If no magnetic field is present, proceed with the
next test.
Testing the actual output of the alternator is known as “Full Field Testing”. This can
be accomplished by jumping a positive 12VDC current to the field terminal at the
rear of the alternator. This test eliminates both the regulator and the harness, mak-
ing it easier to isolate your investigation to the alternator.
CAUTION: Ensure that all voltage sensitive equipment is turned off prior to starting the engine. Voltage is unregulated
during this test and could damage sensitive electronics. DO NOT let the engine run any longer than necessary to detect
charging. If the system is not charging, remove the alternator and have it inspected by a qualified alternator shop, or call
Balmar for warranty evaluation.
To test the alternator:
Clip a jumper wire to the positive post of the alternator, or on the battery side of the isolator (if an isolator is in use).
Use a SHIELDED alligator clip for post attachment. Unintentional contact between the alligator clip and the alternator
case could result in damage to your electrical system.
Disconnect the field/stator plug from the rear of the alternator and attach the other end of the jumper wire to the al-
ternator’s Field terminal (F). Attach a female spade connector to the field end of the wire for a solid connection. CAU-
TION: Do not allow the wire to contact the case while it is attached to the positive post. The case is grounded and
severe damage could occur.
The regulator is now bypassed. When the ignition is engaged and the motor is started, the voltage should rise and
charging current should be present.
The motor should be run long enough to determine that charging voltage is present. Unregulated voltage can rise
quickly. Do not allow extended unregulated charging to occur without carefully monitoring voltage levels. If the alterna-
tor fails to generate voltage during field testing, a malfunction of the alternator is likely. Contact your local alternator
repair shop or Balmar’s technical service staff for recommendations.
Conclusion
If your readings differ substantially from the “Expected Readings” listed in the troubleshooting charts, the regulator may
be malfunctioning, or there may be a continuity problem. Contact our technical support staff at (360) 435-6100. If you
determine that repair service is necessary for either your alternator or regulator, please gather the following information
before contacting our service technicians: Make and model of alternator. Model of voltage regulator and date of mfg. (date
punched on rear side label of regulator). Voltage readings on red, brown and blue wire at regulator with engine off, key on.
Voltage readings on red, brown and blue wire at regulator with engine running at a fast ideal 1400 rpm.
NOTES:
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