What is a Voltage Regulator? What are the signs of a voltage regulator failure? How to test a voltage regulator ?….
The components of all automotive charging systems regulate the voltage output of an alternator. An external electromechanical voltage regulator is used in older cars to perform this function. Modern cars use either an electronic regulator (or a computer, sometimes both).
The voltage regulator, like any other part of your car can fail. If this happens, you will notice some of the symptoms you need to address immediately.
What is a voltage regulator?
Understanding how the charging system works is key to understanding how voltage regulators function will allow you to better comprehend the subject.
Most people know that the alternator’s primary function is to charge and provide electricity to the car’s electronic system. These tasks are accomplished by electromagnetic induction which generates electricity from the magnetic field.
The alternator consists of three main components: the rotor; the stator; and the diode Bridge. The alternator’s rotating component, the rotor, is composed of three sets of field coils that are located behind opposing magnetic poles. The stator includes three sets of fixed coil windings as well as a laminated center. The diode-bridge, on the contrary, is composed of diodes which act as one way electrical check valves.
Through a series slip rings and brushes, the rotor’s magnetic field coil receives an electrical current. The magnetic poles on the rotor strengthen this current, creating a magnetic magnetic field. Each time the engine turns on, the vehicle’s drivebelt rotates the rotor via the pulley located in front the alternator. As the rotor spins, the stator creates an alternating voltage. The diode bridge converts AC (alternating current) into DC (direct current) that the car’s electric system can use.
This puzzle has one more piece. The alternator must produce enough voltage to charge the battery in order for the charging system to function properly. This voltage should not exceed the limits of safety and damage to the vehicle’s electrical system. A voltage regulator is used to charge the car’s battery. The voltage regulator regulates the current flowing through the field coil of rotor, and the voltage output of alternator.
Many cars used voltage regulators up until the mid-1970s. Modern cars often use electronic regulators to control the alternator’s output voltage. These electronic regulators can be integrated into the alternator, a laptop, or both. Computerized systems don’t have a separate voltage regulator. The whole regulator assembly is integrated in the engine computer.
What are the Signs of a Defective Voltage Regulator Failure?
Over time, voltage regulators can become worn out and eventually fail like all electronic devices. The regulator’s life span can be reduced by charging system issues such as a weak battery, or a faulty alternator.
You may notice the following symptoms if your voltage regulator is defective. You may also experience other symptoms similar to a faulty voltage regulator. Before replacing any part, it is important to thoroughly inspect the whole system.
Battery problems
An alternator that is not properly calibrated can cause it to charge the battery too low or excessively. Insufficient charging can cause the battery’s to become completely dead or discharged. Overcharging can result in internal battery damage.
Warning lights on the instrument panel
The instrument panel’s charging system warning lamp will illuminate if the voltage regulator fails. An overcharging of the system or a faulty voltage regulator could also cause the check engine and other warning lights to flash.
Lighting Issues
You will notice that your headlights and other lights dim when the regulator causes a low-voltage system. The lifespan of bulbs could be reduced if the regulator produces a higher than normal output. Flashing lights might appear brighter than usual.
Other Strange Events in the Electrical System
There are many electronic parts in your car that are powered by the charging voltage. A faulty voltage regulator can lead to many electrical problems in modern computer-controlled vehicles. Circuit failures can also be caused by an overcharge condition.
How do you test a defective voltage regulator?
A handheld digital tester is often used by professional mechanics to diagnose problems with charging system. You may not be able to access such a device so you will need a digital multimeter to test your charging system.
Connect the black lead of your multimeter to the battery’s negative terminal and the red lead the positive terminal to check the voltage output. The battery’s lowest voltage should not exceed 12.2 volts when the engine is off. If the charging system is not properly tested, it will not work.
Once you have checked that your battery is charged, start the vehicle. Increase the engine speed to 1,500-2,200 RPM. The alternator should be charging, and the regulator working correctly. All lights and accessories must be turned off. For the precise specifications of your vehicle, it is recommended to consult a repair manual.
A low output voltage on the charging system could indicate a problem with the regulator, faulty alternator or loose belt. A faulty regulator is usually indicated by a high output voltage, but this can also be due to a problem in the regulator’s control circuit.
Most voltage regulators can be integrated into the alternator. Most mechanics will replace the whole alternator if the regulator stops working. Older vehicles have the voltage regulator mounted in the fender. Modern vehicles don’t have a voltage regulator. Instead, the engine computer controls the alternator output.
The price of an alternator will depend on what make and model your vehicle is. You can save money by replacing the alternator yourself if you have all the tools and knowledge.
The vehicle might continue to run if the voltage regulator is defective, but it won’t for very long. The battery will eventually die if the regulator causes an undercharge system. The regulator may cause overcharging which can lead to performance issues that will prevent the vehicle from being driven. A higher charging output than normal can cause damage to the battery and other electronic parts.
