Alternator Regulators: Testing

NOTE: Battery specific gravity should be above 1.200 for a proper regulated voltage check. Charge battery or use a good test battery before testing regulator.

NOTE: Where tester (C-4133) is available, use adapter (C-4341) to switch circuit of regulator to be tested. Adapter (C-4341) has a three position switch to select regulator part number of regulator installed. Follow manufacturers test procedures.

On Models without field-loads relay, connect positive lead of voltmeter to terminal of ballast resistor with blue or blue-black wires connected to it. DO NOT remove connector from ballast resistor. On models with field-loads relay connect positive lead of voltmeter to positive post of battery. Connect negative lead to a good vehicle ground.
Start and run vehicle at 1250 RPM with all lights and accessories turned off. Check voltmeter, regulator is working properly if voltage readings are within specifications.
If voltage is not within limits or is fluctuating, check that regulator has a good ground. With engine off, disconnect regulator terminals. Turn ignition on, but do not start engine. Battery voltage should appear at both blue and green leads of connector. On vehicles with field-loads relay, check for proper operation of relay. If all tests are satisfactory, replace regulator and repeat tests.

To test field-loads relay, disconnect wiring harness connector at voltage regulator. Connect ground lead of voltmeter to a good vehicle ground and turn ignition switch on, but DO NOT start engine. If battery voltage is measured at terminals, relay is working correctly. If voltage is not present at connector and circuit wiring checks all right, relay is malfunctioning and must be replaced.

SPECIFICATIONS

Ambient Temperature⁽¹⁾

Voltage Range

-20°F

14.9-15.9

80F

13.9-14.6

140°F

13.3-13.9

Above 140°F

Less than 13.6

⁽¹⁾	Ambient temperature is measured 1/4" from regulator.