Regulator Output
Make certain alternator belt is correctly tensioned, and all charging connections are clean and tight. Connect voltmeter to battery, turn off all electrical loads and note battery voltage. Run engine at 1800-2000 RPM for several minutes and note voltage reading. If voltage reading is 1-2 volts higher than battery voltage, regulator is satisfactory. If voltage reading is not within given range, replace regulator. If reading is satisfactory, turn on headlights, and turn heater blower motor (or air conditioner) to high speed. Voltage should not decrease more than 0.5 volt. If voltage drop exceeds 0.5 volt, replace regulator.