Spend £50 save & 10% with code SAVE10, spend £100 & save 15% with code SAVE15. Click here to browse our Spring Essentials for Garden, Roadtrip, Car Cleaning & more. T&Cs apply.

Alternator

The alternator works by charging up the battery to power the starter motor, ignition and all other electrical components, replacing the generator used in pre-1960s cars. If this fails, your car's electronics will follow. Replace yours with one of the options below.
Please wait a short moment whilst we retrieve your vehicle details.

Enter your registration or select your vehicle

Find compatible parts faster, using the vehicle finder

Find compatible parts faster, using the vehicle finder below

Enter your registration or select your vehicle

Find compatible parts faster, using the vehicle finder

If your car starts to die – the lights dim; the radio stops – chances are it’s the alternator that’s at fault, not the battery itself as people usually assume.

The alternator is located near the front of the engine and is driven by the crankshaft. The four components of the alternator are the stator, rotor, diode and voltage regulator. The rotor spins inside the stator, producing electricity, which is converted by the diode from AC to DC current to be used by the car’s battery. The voltage regulator makes sure the current flowing to the battery does not get too high and ‘cook’ the battery.

If the charging voltage is too low in the alternator, the charging system could fail, causing the car to break down. Factors that might affect the charging voltage are drained batteries or worn/loose cables. It’s always best to check out the whole charging system – battery, voltage regulator and alternator – if power fails. If it turns out you need to replace the alternator, we have a large range of high-quality products at good prices to suit your needs.
Help