Where is the Voltage Regulator Located on an Alternator?

Q: Where is the Voltage Regulator Typically Located?

A: Older voltage regulators were a unit mounted on the car body. GM moved their voltage regulator into the alternator body in the mid 1970s. Ford moved their voltage regulator into the alternator in the early 1980s. Chrysler moved their voltage regulator into the engine controller in the mid-1980s on some of their platforms.

Since about 2000, most platforms have the voltage regulation built into the PCM, so you might or might not have a voltage regulator on your vehicle. Bear in mind that the exact location of the voltage regulator will vary from vehicle to vehicle. If you’re struggling to find your voltage regulator, your best bet would be to consult your vehicle owner’s manual for the exact location.

The voltage regulator is the part of the charging system responsible for regulating the current in the alternator field (the spinning rotor driven by the pulley). It keeps track of system voltage and regulates the alternator field current to maintain a target voltage of about 14.5 volts.

Tips on How to Access the Voltage Regulator

To access the voltage regulator, all you need to do is park your vehicle, disconnect the car battery, and check the engine compartment. It’s helpful to look up the voltage regulator for your vehicle on CarParts.com so you can determine what it looks like.

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Some voltage regulators are easy to change, others, not so much, so make sure you don’t get in over your head to begin with. Also, make sure you know the voltage regulator is the problem before you even start. Something as simple as an open wire between the regulator and the battery light in the cluster can cause the regulator not to “turn on.” There are many other possibilities as well.

Don’t forget to disconnect the car battery before replacing the voltage regulator. Reconnect it after the job is done. Test your vehicle’s electrical system with a multimeter to confirm that your new voltage regulator is working as intended.