Symptoms of a Bad Voltage Regulator

by Jonathan Lister
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A voltage regulator maintains an even flow of electrical power to an automobile's electrical systems, including the headlights, dashboard components and the stereo. When the parts fail or begin to show symptoms of failing, it can have far-reaching implications to the viability of the automobile. You may notice dimming headlights or unpredictable engine function and even a dead battery. As soon as you notice the symptoms, take the vehicle for an in-depth inspection before the problem leaves you on the side of the road.

Dimming or Pulsing Lights

A damaged or failed voltage regulator can rapidly diminish the alternator's ability to cycle power from the battery. This may cause the vehicle to experience dimming or pulsating external systems, such as headlights and dashboard elements. In addition, the "check engine" or "battery" light may appear on the dashboard when the initial failure is detected by the vehicle's on-board computer.

Dead Battery

A burned-out voltage regulator will diminish the vehicle battery's ability to charge or stop it altogether. You will quickly find the vehicle unable to start due to a dead battery. If the battery is recharged, the vehicle will start, although the faulty voltage regulator will only cause the battery to lose power rapidly. In this case, the vehicle should immediately be taken to a mechanic once the battery has been recharged or the car has been jump-started to have the voltage regulator replaced.

Unpredictable Engine Performance

Some aftermarket voltage regulators have experienced problems working in factory-built systems. Engine stalling, sputtering and intermittent acceleration will occur when the vehicle's voltage regulator is unable to handle the power put out by the vehicle's stock (and faster-moving) alternator. This causes the regulator to burn out quickly because it was overworked. Have either a certified mechanic or someone with extensive knowledge of the vehicle being modified look at the aftermarket parts.

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