A warning light on the dashboard tells you something is wrong, but not what. NRH Autoworks carries out vehicle diagnostics and electrical repairs at our garage on Windsor Road in Bray, helping drivers from Maidenhead and the surrounding area get to the bottom of warning lights, starting problems and electrical faults.
The more you can tell us, the faster we get to the cause. Enter your registration on the enquiry form, note which light is showing and describe how the car is behaving. A photo of the dashboard is helpful too. We'll get back to you by phone or email to arrange a diagnostic check.
What we can help with
- Computer diagnostics and fault code reading
- Engine, transmission, ABS, traction control and airbag warning lights
- Battery, alternator and starter motor faults
- Wiring faults, short circuits and poor earths
- Electric windows, central locking and wipers
- A plain-English explanation of what we've found
When to request a diagnostic check
- The engine management light is on or flashing
- An ABS, airbag, battery or other warning light won't go out
- The car has gone into limp mode and lost power
- Rough idling, misfiring, hesitation or stalling
- The engine turns over slowly, or just clicks
- An electrical fault that comes and goes
- A window, door lock or wiper that has stopped working
A fault code is where diagnosis starts
Modern cars monitor themselves constantly. Control units for the engine, transmission, ABS, traction control and airbags each store a fault code when a reading falls outside its expected range, and often switch on a warning light. Reading those codes through the car's diagnostic (OBD) socket is the first step, but a code describes a symptom rather than a failed part. One pointing at an oxygen sensor may be caused by the sensor, its wiring, an air leak or a fuelling problem elsewhere.
That's why simply replacing whatever part the code happens to mention so often fails to fix the car. Proper diagnosis means using the code as a lead, then testing (checking live data, wiring, connections and the components themselves) until the real cause is confirmed and we're confident the repair will fix it.
Starting and charging faults
A car that won't start usually comes down to one of three things. The battery stores the energy, the starter motor uses it to turn the engine, and the alternator puts it back once the engine is running. A tired battery, a worn starter and a failing alternator can look identical from the driver's seat, a click, a slow churn or a battery light, so we test each part of the circuit before replacing anything. Quite often the fault is a poor connection.
Wiring faults
Wiring problems are some of the most time-consuming faults to trace. A short circuit blows fuses or drains the battery overnight. A corroded earth connection can make several unrelated systems misbehave at once. A loom that has chafed through, or been damaged by water or rodents, produces faults that come and go with bumps and weather. Finding them means working through the circuit methodically with wiring diagrams and a meter. We'll keep you informed as we go, because this work is hard to predict at the outset.
Body electrics, and what to tell us
Everyday electrical items fail too. A window that drops into the door or moves slowly usually has a worn regulator or a faulty switch. A door that won't lock with the rest points to its central locking actuator. Wipers that stop mid-sweep or won't park suggest the wiper motor or its linkage. We test before replacing, because a broken wire where the loom passes into the door can mimic all of these.
Intermittent faults are the hardest to find, because the car may behave perfectly in the workshop. Details help a great deal: does it happen when the engine is cold or hot, at a particular speed, in wet weather or over bumps? Has any work been done recently? Put whatever you've noticed in your enquiry, and once we've found the cause we'll explain it before doing anything further.
Diagnostics & Electrics: common questions
Where can I get a car diagnostic near Maidenhead?
We carry out diagnostics at our garage at 274 Windsor Road, Bray, SL6 2DT, on the A308 between Maidenhead and Windsor. Enter your registration on the enquiry form, tell us which warning light is on and how the car is driving, and we'll contact you by phone or email to arrange a time.
Will a diagnostic check tell you exactly what's wrong?
It tells us where to look. Fault codes narrow the search to a system or circuit, and further testing confirms the actual cause. Some faults are found quickly; others, particularly intermittent ones, take longer to trace. We'll keep you informed about what we've found and what we'd recommend next.
My warning light came on and then went off again. Should I still get it checked?
It's worth doing. The car normally stores the fault code even after the light goes out, so there's still useful information to read. A light that comes and goes often points to an intermittent fault, and those tend to become permanent. Let us know when it happened and what you were doing at the time.
Can I keep driving with the engine management light on?
If the light is steady and the car drives normally, a short, gentle journey is usually fine, but have it checked soon. If it's flashing, the car has lost power, or a red warning light is showing, stop when it's safe and get advice before driving further.
Is the diagnostic check separate from the repair?
Yes. The diagnostic check identifies the cause of the fault. Once we know what's wrong, we'll explain it and talk you through what the repair would involve, and you decide whether to go ahead. We don't carry out repair work without discussing it with you first.