Beijing Yinghuafei International Trading Company

A part of the charging system that controls how much electricity the alternator puts out (See Alternator). The voltage regulator on today's cars is an electronic black box, which means you can't adjust it or repair it if anything goes wrong with it. On most new vehicles the voltage regulator is located inside the alternator and cannot be replaced separately. On some cars, the powertrain control module (PCM) regulates the alternator. A defective regulator can cause the alternator to produce too much voltage (which can damage the battery, lights and electronic components) or it can prevent it from making enough voltage to keep the battery fully charged. The toughest challenge when diagnosing a charging problem is to figure out whether it's the voltage regulator or alternator that's at fault. Using a procedure called "full fielding the alternator" that causes the alternator to put out maximum current will reveal which component is at fault.