A23 crawling, wet dips by Norbury Brook and charging faults
London Road through Norbury is a slow red route, stop and go from Hermitage Bridge down to Thornton Heath Pond, and it's where many local cars spend most of their running time. Crawling in traffic keeps the engine near idle, which is when an alternator produces the least current. Add a school run in term time, with the heater, lights and wipers on, and a car with a weakening alternator can finish each trip with less charge than it started with.
Norbury Brook, which runs under London Road at Hermitage Bridge, can rise quickly after heavy rain, and surface water collects in low spots on the surrounding roads. Driving through deep standing water can splash an alternator that sits low on the engine, and water gets into the bearings and brush gear or corrodes the terminals. On the terraced streets of the Norbury Cottage Garden Estate, where cars are parked nose to tail and used for short journeys, a small charging fault can take weeks to become obvious.
When a car comes in from Norbury, we check the battery, the alternator's output at idle and under load, and the condition of the belt, tensioner and pulley. We look for tell-tale corrosion on the main charging terminal and earth straps, because a bad connection can mimic a failed alternator. We'll show you what we find and give you a written quote. Parts are OE-specification, and the belt is renewed as standard.
At around 5.5 miles, it's a fair drive to Hackbridge with a failing alternator: down the A23 to the Lombard roundabout, west on the A236 across Mitcham Common, then south on Carshalton Road. If the light is already on, it's usually wiser to let us arrange collection. Stopping on the red route with a dead battery is no fun for anyone. Repairs carry our 3-month workmanship warranty.