Wallington Alternator Repairs, Six Minutes Up London Road

We're about six minutes from Wallington town centre, straight up Manor Road and London Road to Soho Mills in Hackbridge. If the battery light is on or the car won't start, we'll test the charging system before quoting, and alternator replacement starts from £280.

  • ★★★★★ 4.9/5 from 87 Google reviews
  • ~6 min from Wallington
  • Mon–Sat 8am–8pm
Mercedes with the bonnet up for electrical work at KITH Cars Garage & Bodyworks, Hackbridge

School runs, parked-up side streets and a flat battery

With several grammar schools in town, Wallington mornings are dominated by the school run. Plenty of cars do a mile or two in queues on Woodcote Road or around Wallington Square, then sit on a driveway until the afternoon. The same goes for South Wallington, where Plough Lane and Sandy Lane South feed traffic towards Roundshaw. It's a classic pattern for undercharging: every trip starts with a big draw on the battery, and the alternator never gets enough steady running to put it back.

If the alternator is starting to fail, those trips make it worse. Worn brushes or a failing regulator may produce enough current on an open road but not at the low revs of a school-run crawl. You might notice the lights dim when you stop, or the battery warning flickering when the heater and wipers are on. Residential side streets lined with parked cars, often single-file, are also the worst place to need a jump start, because there's nowhere to put the second car.

We don't guess. A charging test covers battery health, alternator output at idle and under load, and the condition of the belt, tensioner and connections. If you've recently fitted a new battery and still have problems, we'll check whether it has been registered on cars that need it, as that affects how the car charges it. Once we know the cause, you get a written quote, and the belt is renewed with any new alternator.

Being this close has advantages. You can drop the car off and walk back through Beddington Park, or we can collect it from home if it won't start. From the town centre, it's Woodcote Road north onto Manor Road, over the A232 at Wallington Green and along London Road to Soho Mills, about 1.7 miles. Repairs are covered by our 3-month workmanship warranty.

Alternator Replacement: what’s involved

The alternator is driven by the auxiliary belt and generates electricity whenever the engine runs. It powers the car's electrics on the move and recharges the battery after starting. Inside, a regulator controls the output, diodes turn the alternating current it makes into direct current, and brushes feed the rotor. Many diesels and stop-start cars also use a freewheel or decoupler pulley that smooths out engine vibration.

On older cars the alternator simply holds the system at a steady voltage. Many modern cars use smart charging, where the engine ECU varies the alternator's output to save fuel, charging harder when you slow down and easing off when you accelerate. That makes testing more involved, because a reading that would look wrong on an older car may be normal. When an alternator fails, the car runs on battery power alone, usually for a short time before it stops.

From £390Written quote first
1.5–4 hoursTypical time in the workshop
3 monthsWorkmanship warranty
4.9★87 Google reviews

Signs your alternator is failing

Battery warning light on

The red battery light while driving usually means the charging system isn't working, not that the battery itself is faulty. Get it checked promptly.

Repeated flat batteries

A car that needs jump-starting, even with a new battery, often has an alternator that isn't charging properly.

Dim or flickering lights

Headlights or dash lights that dim at idle and brighten with revs can point to low or unstable output.

Electrical faults while driving

As voltage drops, systems start to misbehave: warning lights appear, the radio cuts out and power steering or stop-start may stop working.

Whining or grinding noise

A whine that rises with engine speed can be worn bearings or the regulator. A rattle from the pulley can mean a failed decoupler or freewheel pulley.

Belt squeal

A squealing belt may be slipping on the pulley, which stops the alternator charging properly. It can also point to a worn tensioner.

Hot or burning smell

An overheating alternator or a slipping belt can give off a hot electrical or rubber smell and should be checked straight away.

When should it be done?

Alternators don't have a set replacement interval. Many last well over 100,000 miles, but bearings, brushes, regulators and pulleys wear, and oil or coolant leaks can shorten their life. Have the charging system tested if the battery light comes on, the battery keeps going flat or you hear a whine from the front of the engine. It is also worth checking whenever a new battery is fitted, so a charging fault isn't mistaken for a bad battery.

  • Battery warning light on while driving
  • Flat battery that returns after recharging or replacement
  • Whining, grinding or rattling from the alternator or its pulley
  • Oil or coolant leaks onto the alternator
  • Whenever a new battery is fitted

How we replace an alternator

  1. Check-in and symptomsWe ask about warning lights, flat batteries and noises, and whether a new battery has been fitted recently.
  2. Charging system testWe test battery health, alternator output under load and voltage ripple, and read any charging codes from the ECU, allowing for smart charging systems.
  3. Check belt, pulley and wiringWe inspect the auxiliary belt, tensioner and pulley, and check the main charging cable and earth connections. A bad earth can look like a failed alternator.
  4. Written quoteWe show you the results and give you a written quote. Work only goes ahead once you approve it.
  5. Remove the old alternatorWe disconnect the battery, remove the belt and take out the alternator. On some engines this means removing other components for access.
  6. Fit the new unit and beltWe fit the new alternator and a new auxiliary drive belt, check the tensioner and idler pulleys, and tighten the terminals to the correct torque.
  7. Retest and road testWe retest the charging voltage at idle and under electrical load, clear any codes, and road test the car to confirm correct charging.

Parts we fit

We fit new or quality remanufactured alternators to OE specification, from reputable manufacturers such as Bosch, Valeo or Denso. The output rating and pulley type must match the original, especially on stop-start and smart charging systems. We always fit a new auxiliary drive belt, from suppliers such as Gates, Dayco or Continental, and replace the tensioner if it is worn.

  • New or remanufactured OE-specification alternators
  • Correct freewheel or decoupler pulley where fitted
  • New auxiliary drive belt
  • Belt tensioner and idler pulleys where worn
  • Charging cable and earth repairs as required

How long it takes

1.5–4 hours

Many alternators can be replaced in a couple of hours. On some engines the alternator sits low down or behind other components and takes considerably longer. We will give you a time with your quote.

What’s included

  • Full charging system test before replacement
  • Battery health check
  • New auxiliary drive belt fitted
  • Tensioner and pulley inspection
  • Charging system retest after fitting
  • Road test

From Wallington to our Hackbridge workshop

From Wallington town centre, head north on Woodcote Road (A237) past the station onto Manor Road, cross the A232 at Wallington Green and continue straight along London Road (A237) to Hackbridge. Soho Mills is on London Road near Hackbridge station.

From Wallington town centre, go north on Woodcote Road, Manor Road and London Road (A237) to Hackbridge, about six minutes. If the car won't start, we can collect it.

Directions from Wallington

About Wallington

Wallington is a settled residential suburb in the east of the London Borough of Sutton, with a compact town centre around Woodcote Road, Stafford Road and Manor Road. Housing is mostly Victorian, Edwardian and interwar semis and terraces, with flats near the station and the rebuilt Roundshaw estate to the south on the former Croydon Airport site. It is popular with families, helped by well-known grammar schools, and commuters using Wallington station. Driving is generally straightforward, though the town centre and school streets get busy at peak times.

Places nearby: Wallington Town Hall, Wallington Green, Holy Trinity Church, Beddington Park, Wallington Square, Wallington station

Postcodes: SM6 · London Borough of Sutton

More about KITH for Wallington drivers

Alternator Replacement in Wallington: your questions answered

I've just fitted a new battery and it's flat again. What's wrong?

It's usually either an alternator that isn't charging properly or a drain while the car is parked. On some newer cars, a new battery that hasn't been registered can also be charged incorrectly. We test for all three.

Can I drop the car off before the school run?

Yes. We open at 8am Monday to Saturday, and from most of Wallington the walk home is short. We'll ring you with the test results and a quote before any work starts.

Could a failing alternator damage my new battery?

It can. If the alternator isn't charging, the battery is repeatedly drained deeply, which shortens its life. A faulty regulator can also overcharge it. Fixing the alternator early protects the battery.

Could it just be the battery?

It could. Batteries and alternators produce similar symptoms, which is why we test both, along with the belt and wiring. A new battery on a car with a failing alternator will soon go flat again.

Why replace the drive belt too?

The belt has to come off to change the alternator, and an old belt is often glazed or cracked. Fitting a new one at the same time costs little extra and avoids paying for the same labour again when it fails.

Can I drive with the battery light on?

Only a short distance, and with as few electrical loads on as possible. The car is running on battery power and could stop without much warning. If the light came on with a squeal or loss of power steering, the belt may have failed, so stop and get advice.

New or remanufactured?

A quality remanufactured alternator is rebuilt with new wear parts and tested to OE specification, and is a sensible choice for many cars. We'll tell you which options are available for yours and the price of each.

What is smart charging?

On many modern cars the engine ECU controls alternator output, reducing it when the battery is well charged and increasing it when you slow down, to save fuel. It means voltage readings vary more than on older cars, so testing needs to take this into account.

Price your alternator replacement now

Enter your reg and we’ll look up your car and price the job from our own labour rates and the book time for your model. Then book it in with a fixed written quote before any work starts.

  • Free, about 30 seconds, no sign-up
  • Parts, labour and VAT included
  • 3-month workmanship warranty
  • Collection from Wallington can be arranged
“It’s rare to find a garage you can truly trust. Fair price, brilliant customer service.”Thinushan K. · ★★★★★ Google

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