EXPERT IN AUTO PARTS
7 August 2025 (updated) Table of Contents
The alternator plays a key role in turning engine power into electricity for everything from your headlights to the battery. Knowing how it works helps you spot problems early and avoid getting stranded with a flat battery.
An alternator is your vehicle's central electrical component, responsible for converting mechanical energy from the engine into electrical current. It provides essential power to all of your car's electrical systems, including the headlights, infotainment, fuel injection, and ignition systems. At the same time, it continuously recharges the battery to ensure reliable performance. You can think of it as your car's dedicated energy source, operating whenever the engine is running to keep everything functioning smoothly.
The car’s generator is a compact, cylindrical component typically made of silver or grey aluminium. It is usually mounted near the front of the engine and is easily identified by its pulley wheel, which is connected to the serpentine belt. Around its housing, you'll notice cooling fins or vents, along with several electrical connectors extending from one end. The aluminium casing plays a critical role in dissipating the heat produced during operation, while the generator's durable construction allows it to endure the demanding conditions of the engine bay.
Your car's generator is its electrical lifeline, providing the power needed to keep all your vehicle's electrical systems running and your battery charged. As the engine turns, the alternator converts that motion into electrical energy. This ensures your headlights stay bright, your dashboard displays remain active, and your engine control systems function properly. If the generator fails, your battery will quickly drain, leaving you unable to start the engine or use critical features like lights and indicators.
The generator serves as your car's dedicated source of electrical power, delivering a continuous current to operate all electronic systems and keep the battery properly charged throughout your drive.
An alternator charges your car battery through a sophisticated energy conversion process that transforms mechanical rotation into electrical power. The spinning rotor creates a magnetic field that induces alternating current in the stator windings, which built-in diodes then convert to direct current suitable for your car's electrical systems.
A car voltage regulator ensures the charging current remains within safe parameters, preventing overcharging whilst maintaining optimal battery condition for reliable engine starting and electronic system operation.
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LUCAS Alternator
14V, 70A, M8 B+, M5 D+, 0230, Ø 55 mm
Article number: LRB00436
£82.49price incl. 20% VAT, excl. delivery costs
-13%
Article number: A6365PR
compared to
RRP
£143.45
£124.49price incl. 20% VAT, excl. delivery costs
LUCAS Alternator
14V, 50A, M6 B+, L, 0004, Ø 56 mm
Article number: LRA00471
£67.49price incl. 20% VAT, excl. delivery costs
-44%
DENSO Alternator
14V, 120A, Ø 54 mm
Article number: DAN1119
compared to
RRP
£324.60
£178.99price incl. 20% VAT, free delivery
-9%
Article number: 695.002.035.050
compared to
RRP
£81.54
£73.99price incl. 20% VAT, excl. delivery costs
You'll find the generator prominently located in your vehicle's engine bay, usually mounted to the side of the engine block and driven by the serpentine belt system. Depending on your car's design and engine layout, it may be positioned on either the left or right side. Its placement is generally accessible for routine inspection or replacement, although in tighter engine bays, other components may partially obstruct the view. To identify it, look for the round pulley connected to the belt and a set of electrical wires leading into the unit.
A generator comprises several precision-engineered components that work harmoniously to generate electrical power for your vehicle. The key components include:
Each component plays a vital part in maintaining your vehicle's electrical supply – from the rotor's magnetic field generation to the voltage regulator's precise control of charging output.
A generator typically lasts between 80,000–150,000 miles, translating to approximately 7–10 years of normal driving conditions. However, your alternator's lifespan depends significantly on your driving habits, maintenance routine, and the electrical demands you place on your vehicle's systems.
The correct generator for your vehicle depends on your car's specific year, make, model, and engine variant. Check your owner's manual or the existing alternator's part number for exact specifications, or use online parts catalogues by entering your vehicle details. Consider any electrical modifications you've made – aftermarket sound systems, additional lighting, or other accessories may require a higher-output generator than the original equipment specification to handle the increased electrical load effectively.
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-45%
DENSO Alternator
14V, 105A, Ø 60 mm
Article number: DAN1375
compared to
RRP
£394.61
£217.00price incl. 20% VAT, free delivery
LUCAS Alternator
14V, 140A, M8 B+, L-DFM, 0248, Ø 54 mm
Article number: LRA03583
£99.99price incl. 20% VAT, excl. delivery costs
-27%
Article number: 586.002.055.090
compared to
RRP
£119.62
£86.49price incl. 20% VAT, excl. delivery costs
-12%
Article number: A0632PR
compared to
RRP
£130.80
£113.99price incl. 20% VAT, excl. delivery costs
BOSCH Alternator
14V, 150A, B2+(M8), L, DFM, PL72, excl. vacuum pump, Ø 54,3 mm
Article number: 0 986 047 360
£156.49price incl. 20% VAT, free delivery
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