Alternators - Car - Ford Focus MK2 (2008-2011)

How to recognize a bad alternator?

A faulty alternator usually shows several common symptoms:

• Battery warning light on the dashboard (red battery icon)

• Weak or discharged battery even after longer drives

• Difficult or failed engine starts

• Flickering or dimming headlights

• Unstable operation of vehicle electronics (radio, air conditioning, dashboard)

What is the correct voltage?

A properly working alternator should maintain system voltage in the following range:

• At idle: approx. 13.8 – 14.5 V

• At higher RPM: up to around 14.8 V

• Voltage constantly below 13 V → alternator is not charging

• Voltage above 15 V → faulty voltage regulator, risk of damaging electronics

Development of Ford alternators

Older Ford models used simple alternators with integrated voltage regulators. Newer vehicles – such as the Focus MK2, Mondeo MK4, and Fiesta MK7 – feature smart charging, where the alternator communicates with the engine control unit (PCM – Powertrain Control Module) and adjusts charging according to engine load and electrical consumption.