Alternator Repair in Derry

The car's alternator performs a simple but vital job: to keep your car's battery charged. The battery is responsible for starting the car, spark plugs, lights, electrics, and sometimes power steering - quite a job - so it's essential that it's topped up - and that's what the alternator does.

The alternator acts like a small generator: the engine spins, and the alternator turns that spinning motion into electricity. The most common problems are worn brushes (the component that maintains constant electrical contact with the spinning alternator) and a failing voltage regulator (which ensures that the charge is sent to the battery at the correct voltage.)

Common signs of car alternator problems include the 'charge' or battery lights flashing on the dashboard, flickering or dimming headlights and interior lights and a growling or whining noise under the bonnet.

An alternator can be rebuilt as opposed to replaced, however in truth the difference in cost is often quite small. Either way the most common repair cost is around £150-200.

A simple way to test an alternator for problems is to do what's known as the headlight test. Park your car with the headlights on or run it in neutral, then rev the engine. If the headlights dim you could well have an alternator problem. A better test is to take your car to a garage, where a car alternator can be tested using a multimeter tool.

If your alternator fails, your car battery won't charge and, very soon, will have insufficient charge to start the car.