Nissan Sentra Alternator Voltage Regulator Replacement Cost

Know what price you should pay to get your vehicle fixed.

The average cost for a Nissan Sentra alternator voltage regulator replacement is between $359 and $394. Labor costs are estimated between $130 and $165 while parts are priced at $229. Estimate does not include taxes and fees.
Note about price: The cost of this service or repair can vary by location, your vehicle's make and model, and even your engine type. Related repairs may also be needed. Talk with a RepairPal Certified shop to learn which repairs might be right for you.

How does an Alternator Voltage Regulator work?

The voltage regulator works with the alternator to make sure that electrical output stays within 13.5-14.5 volts and that the battery stays charged. A vehicle's battery is used to provide power to start the engine, and it is used to smooth out the supply of electricity when the vehicle is running. In time, a battery would lose its charge and die if it had to run all of the systems on a vehicle and if it was not recharged regularly. The alternator is responsible for taking over once the engine starts. The alternator provides power for all of the vehicle electrical systems (with help from the battery in the case of a load spike) and is responsible for keeping the battery in a state of full charge. If the battery gets too weak, the alternator charges the battery. Once the battery is fully charged, the alternator stops charging. The voltage regulator monitors the battery's state of charge and signals to the alternator when it is time to charge and time to stop charging.

What are the symptoms of a bad Alternator Voltage Regulator?

Symptoms of a bad voltage regulator might include a dead battery, dim or pulsing dash lights, or erratic engine performance. Each of these symptoms can also be attributed to other causes, but if the voltage regulator is failing, it can prevent the battery from charging properly or the alternator from putting out the correct voltage for vehicle operation. If the voltage regulator is not signaling to the alternator that it is time to generate a charge, the battery will discharge. A weak or dead battery will not be able to start the vehicle. If the battery drains while the vehicle is running (because the alternator is not putting out a charge), the headlights may dim, the dash lights may dim or pulse, and the vehicle could stall, leaving the steering system powerless and leading to difficulty braking. If the voltage regulator is faulty, a warning light on the dashboard should illuminate.

Can I drive with a bad Alternator Voltage Regulator?

Any time problems occur with the vehicle charging system, immediate attention is required. The voltage regulator is an important component of the charging system. If the symptoms of a bad voltage regulator occur, the vehicle should either be driven to the nearest qualified repair facility, or should be parked and towed. A comprehensive inspection and evaluation of the starting and charging system should be performed.

How often do Alternator Voltage Regulators need replacement?

The alternator and voltage regulator are not maintenance items that have replacement intervals. A factory alternator (with the voltage regulator inside) may last 100k miles or more, however, it is not unusual for an alternator to fail closer to 80k miles due to its moving parts, heat, and internal components that wear.

How are Alternator Voltage Regulators replaced?

In most cases, the voltage regulator (which is located inside the alternator housing) is replaced in conjunction with the alternator. It is possible to replace only the voltage regulator on some vehicles - usually by disassembling the alternator to gain access - but because the other alternator components can wear out over time also, the alternator is commonly replaced. Whether the alternator is to be replaced or only the voltage regulator, the alternator needs to be removed from the vehicle. In order to do this, a technician will need to locate the alternator and remove any components that are in the way. Depending on the vehicle make and model, this could be a significant amount of work; some vehicles have several components that block access to the alternator. In some cases, the vehicle will need to be raised and supported off the ground for underbody access. With the alternator accessible, the technician will remove the serpentine belt, alternator electrical connections, and mounting hardware, taking care not to damage the radiator and other nearby components. Once the alternator is out of the vehicle it can be disassembled (for replacement of the voltage regulator) or simply replaced.

RepairPal Recommendations for Alternator Voltage Regulator issues

RepairPal recommends a professional comprehensive inspection of the vehicle starting and charging system to determine the cause of symptoms similar to those of a bad voltage regulator. If the alternator or voltage regulator need to be replaced, it is advised that the serpentine belt, idler pulley, and belt tensioner be inspected and replaced at the same time.

What to look out for when dealing with Alternator Voltage Regulator issues

Care must be exercised any time the electrical system is being serviced to prevent injury or damage to sensitive vehicle electronics. Other problems, such as dirty and corroded battery terminals, can produce symptoms similar to those of a faulty voltage regulator.

Can I replace the Alternator Voltage Regulator myself?

Access to an alternator can be tricky. There are many surrounding parts that usually need to be removed and there is often very little space to work in. Damage to nearby components - such as the radiator - is possible. Voltage regulator or alternator diagnosis and replacement can be performed on many vehicles by an experienced DIYer, or otherwise left to a repair professional.