Mobile Auto Electrical Repairs Reading & Berkshire

Modern vehicles are substantially more electrical than mechanical. A wiring fault, failed sensor or malfunctioning control module can cause symptoms ranging from a warning light to a complete no-start condition. We carry the diagnostic tools and equipment to trace and repair automotive electrical faults at your home or workplace.

Sensor Faults

Engine sensors provide the ECU with the data it needs to run the engine efficiently. Sensor failure causes the ECU to enter a default or limp mode, often triggering the engine management light and reducing performance.

Oxygen (lambda) sensors — control fuel mixture, affect fuel economy and emissions. P0136, P0141, P0031 and related codes.
Mass airflow (MAF) sensor — measures air entering the engine. A failing MAF causes rough idle, poor performance and lean/rich codes. P0101, P0102.
Crankshaft position sensor — if this fails the engine will not start. P0335.
Camshaft position sensor — causes misfire, rough running and timing errors. P0340.
Coolant temperature sensor — affects fuelling and fan operation. P0115.
ABS wheel speed sensors — trigger ABS and traction control lights. C1234 and related codes.
TPMS sensors — tyre pressure monitor sensors. Require programming after fitting.

Wiring and Earth Faults

Earth (ground) connections corrode over time, especially at chassis attachment points. A poor earth causes:

Erratic dashboard behaviour
Electrical components working intermittently
Instrument cluster faults
Central locking and window motor issues

We systematically voltage-drop test the main earth paths and inspect key connector terminals for corrosion. A corroded earth cable is far more common than a failed component and is often the root cause of baffling intermittent electrical symptoms.

Lighting Systems

Headlight bulb and ballast replacement (halogen, xenon HID, LED)
Headlight levelling motor replacement
Indicator relay and wiring faults
Number plate and interior lighting
Trailer wiring checks and faults

Control Modules

We can test module communication across the vehicle’s CAN bus network. Module failures are relatively uncommon compared to wiring and sensor faults — we eliminate wiring and supply voltage issues before diagnosing a module as faulty.

Charging System

Alternator output testing (13.8–14.4V)
Voltage drop on charging circuit
Battery drain testing — identifying what is draining a battery overnight (parasitic draw test)
Diode failure diagnosis

Pricing

Electrical diagnosis is quoted at £55–65 per hour depending on complexity. Most sensor and wiring repairs are completed within 1–2 hours. We provide a diagnosis report and fixed repair quote before work begins.

Book Auto Electrical Repairs

Call 07305 523333 or use the contact form. Describe the fault — any warning lights, symptoms, when it occurs — and we will give a guide price before attending. We cover all Reading postcodes and Berkshire towns.

Areas we cover

Frequently asked questions

What auto electrical faults can a mobile mechanic diagnose? +

We can diagnose and repair sensor faults (oxygen, MAF, crank, cam, coolant, ABS wheel speed), wiring harness damage, earth cable faults, relay and fuse failures, control module faults, lighting issues and charging system problems. We use a professional multi-system scanner and a digital multimeter for thorough electrical diagnosis.

My car has an intermittent fault that comes and goes — can you diagnose it? +

Intermittent faults are the most difficult to diagnose but we have several tools to help: live data logging during a test drive, voltage drop testing on suspect circuits, and oscilloscope testing for sensor signal quality. In some cases we can leave a logging device on the vehicle overnight to capture a fault that occurs only at specific conditions.

What causes wiring faults in cars? +

The most common causes are rodent damage (mice and rats chewing insulation), corrosion at connectors and earth points, wiring chafing against chassis or subframe components, water ingress at connector points, and age-related insulation cracking in high-heat areas near the exhaust.