SevereAffected: 2004-201170,000–120,000 miles

Ford Focus Mk2 1.8 TDCi — 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

Electric Window Regulator Cable Failure

Minor

2004-201150,000–120,000 miles£100–£200

The cables inside the electric window regulator mechanism fray and snap, causing the window glass to drop into the door frame.

Engine Thermostat Sticking Open

Minor

2004-201160,000–120,000 miles£100–£250

The engine coolant thermostat fails in the 'open' position. The engine never reaches its optimal operating temperature, killing fuel economy.

Starter Motor Solenoid / Brush Wear

Severe

2004-201170,000–130,000 miles£150–£350

The starter motor wears out internally. This is particularly common on vehicles equipped with Stop/Start systems.

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