SevereAffected: 2008-201270,000–120,000 miles

Ford Fiesta Mk6 1.25 82bhp — Alternator / Smart Charge System Failure

Modern vehicles use smart charging systems to reduce engine load, but the complex regulators on the alternators frequently fail.

Severity

Severe

DIY Difficulty

Moderate

Est. Cost

£250–£450

OBD Codes

P0620P0622

Component Diagram

Electrics

Typical layout and location for the Electrics assembly.

Reference Illustration

Symptoms

Red battery warning light on dashboard
'Charging System Fault' message
Systems shutting down (radio, power steering) as battery depletes
Car fails to start

Root Cause

The internal voltage regulator or diode pack on the alternator burns out due to heat and age. Occasionally, a slipping auxiliary belt causes the issue.

How To Fix

Test battery voltage with engine running (should be 13.8V - 14.7V).
If below 12.5V, replace the alternator.
Always replace the auxiliary drive belt at the same time.
Cost: £250-450

Estimated Repair Costs

Repair Option	Est. Cost (GBP)
DIY (parts only)	£100–£180
Independent Garage	£250–£450
Main Dealership	£400–£720

Other Faults on This Variant

Front Wheel Bearing Failure

Moderate

2008-201260,000–100,000 miles£120–£250

Front wheel bearing wear is extremely common on the Mk6 Fiesta. Most examples will need at least one bearing replaced between 60,000 and 100,000 miles.

Power Steering Pump Failure

Moderate

2008-201270,000–130,000 miles£180–£380

The hydraulic power steering pump on the Mk6 Fiesta fails with age and mileage, making the steering very heavy — especially at low speeds and when parking.

Ignition Coil Pack Failure

Moderate

2002-200840,000–90,000 miles£80–£120

The single coil pack block fails, causing a 2-cylinder misfire.

Disclaimer: Repair cost estimates are indicative and based on community data. Always get a quote from a qualified mechanic before proceeding with any repair.