VIII. System Troubleshooting
The majority of charging difficulties can be attributed to damage, corrosion or wear at wires or wiring connections. Before attempting to troubleshoot alternator or regulator issues, be sure to address the following:
1. Remove and clean all charging system electrical connections (positive and negative). Check the voltage regulator’s harness for resistance. Wires and terminals can, and will, become corroded over time, and need to be cleaned or replaced.
2. Charge all batteries to their proper fully charged state, and determine if they are serviceable. If your batteries are flooded-type, use your hydrometer to determine their condition.
3. Check and tighten alternator belt. If the belt show signs of wear or damage, replace it. Always replace existing belts with the finest quality replacements available.

If batteries and wiring are in suitable condition, use the following tests to determine if charging problems are a result of a faulty alternator or regulator. These tests provide an opportunity to isolate the alternator, regulator and wiring harness in order to identify which component may be malfunctioning. In order to perform these tests, you will need a handheld DC multimeter (preferably a digital type). In an emergency, a 12V light bulb or test light can be used to help determine if power or working grounds exist. An amp meter and a battery hydrometer with a thermometer are also helpful diagnostic tools.

A. Voltage Regulator Test
Set your voltmeter to 12VDC and connect the negative lead to the BLACK ground wire at the regulator as shown at right.
1. With the ignition OFF, check voltage on the red (sensing), blue (field) and brown (ignition) wires in the regulator plug.
2. With the ignition in the ON position (engine not running), check for voltage on the red (sensing), blue (field) and brown (ignition) wires. See chart for expected readings.
3. With the ignition in the ON position (with engine running at 1,400 rpm fast idle), check for voltage on the red (sensing), blue (field) and brown (ignition) wires in the regulator plug.
Compare your readings with the values shown in the images at left. If readings on RED or BROWN wires do not match values shown, check 10-amp and 1-amp fuses, wiring and connections back to their sources. If RED and BROWN match expected readings, but BLUE does not, unplug and re-plug four-prong plug and re-test. If the BLUE wire shows zero voltage and the display is not lit, check connections and fusing on the Positive Battery Sense wire. Check voltage at the base of the Positive Battery Sense terminal with your meter.
If voltage is not present on the RED, the BROWN and the Positive Battery Sense Wire, the regulator will not work. If voltage 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 balmar@balmar.net.
If all voltages at the regulator meet expectations, yet the alternator is not producing charging current, we will want to test the alternator. The tests on the following page are recommended for determining alternator functionality.

B. Alternator testing
Test A - 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:
1. 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.
2. 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.
3. After allowing time for the regulator’s start-up delay, place the head of a steel screwdriver near the nut on the pulley shaft 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.
Test B - If there is little or no magnetic pull at the pulley shaft or at the rear bearing, initiate the following test:
1. With the key off and the engine off, remove the large harness plug from the regulator.
2. 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. (See Figure 24.) This bypasses the regulator and tests the alternator and the harness.
3. Using your steel screwdriver, inspect for a magnetic field as described above.
4. With your voltmeter, check for voltage on the blue wire at the alternator. If voltage 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 malfunctioning.
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.

Test C - Full Field Testing
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, making 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:
1. 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.
2. Disconnect the field/stator plug from the rear of the alternator and attach the other end of the jumper wire to the alternator’s Field terminal (F). Attach a female spade connector to the field end of the wire for a solid connection. CAUTION: 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.
3. 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.
4. 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 alternator 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.