This little guy controls the amount of voltage the alternator puts out. Inside the alternator, you've got what's called the rotor, and the field regulator sends varying amounts of electricity to that rotor. By changing that current, it basically tells the alternator how much voltage to generate. It’s constantly monitoring the system voltage and adjusting itself to keep everything steady, usually around 13.5 to 14.5 volts. It's a pretty precise little piece. It’s a key part of your charging system. The battery gets the car started, but after that, the alternator and this field regulator are responsible for keeping everything powered – lights, radio, computer, everything. It also keeps the battery topped up while you drive. Think of it like this: the alternator is the power plant, and the field regulator is the control room, making sure everything gets the right amount of electricity. A failing field regulator can cause all sorts of problems. You might notice dimming headlights, a battery that won’t charge properly, or even the battery draining while the car is off. Sometimes it'll cause a charging system warning light to come on. If it fails completely, you'll quickly drain the battery and the car will stall. It’s not something you want to ignore. You can find replacements pretty easily; a site like Fixparts Online carries a good selection. Ignoring a bad field regulator will almost certainly lead to bigger, more expensive problems down the road, like a ruined battery or needing to replace the alternator itself. Smart choice: Field Regulator (MPN F00MA45225) is backed by a 12-month warranty!

About Bosch

Robert Bosch GmbH is a global leader in automotive technology, offering high-quality parts and systems that enhance vehicle efficiency, safety, and reliability.

Why Choose Bosch?

• Bosch parts are known for lasting a long time, so you won't have to replace them often. • They're made with high-quality materials and tested thoroughly, meaning they perform reliably. • Bosch offers a wide range of parts, so you're likely to find what you need for almost any vehicle. • Mechanics and drivers around the world trust Bosch – it’s a name you can depend on. FixParts Online – Your Trusted Source for Quality Bosch Auto Parts.