My girlfriend took her 04 Focus to Ford because the alternator wasn't charging
the battery (as per the AA, who had to come and help her) and needed replacing.
Now, at this point they ran a suite of tests ( which she had to pay a fair bit
of money for), which confirmed that the alternator was not charging the battery.
They replaced the alternator, and the battery.

Now, along with the alternator problem, there was a horrendous noise, which Ford
said they'd fixed, but when she took the car home, the noise was still there,
albeit a bit quieter. She took the car back to Ford, who had the car for a
couple of days, and said they'd replaced a wheel bearing. THis did fix the noise
problem.

She picked the car up AGAIN from Ford, and within about 5 miles, the battery
light started to flash on and off constantly, something that had never happened
before.

She took the car back to Ford, who after doing some tests said that the new
alternator was overcharging ( at about 17V) and needed replacing. They then said
that the PCM had been damaged and needed replacing at a cost of over £600 to
her, as they said it was the old alternator that had caused the problem.

Can anyone help? IS this really likely, or is it more likely that the new
(overcharging) alternator will have caused the problem? What can we do? WHo can
we speak to? We've already paid over £500, and we think Ford are trying to screw
us over.

By the way, it was Lookers Ford in Chelmsford, if anyone is interested.