Please bear with me, whilst I try to list everything.

This car drives superb can not fault it.

However at standstill or coming to a stop, thats when things go wrong.

If car is at standstill ticking over, and I switch on headlights, or heater, or wipers, infact if I use anything electrical, then engine struggles and shakes, and lights go dim.

I have a brand new silver calcium battery, and brand new bosch alternator.

I changed fuel filter, as someone told me it could be a fuel starvation, I changed this (old one was full of sludge when i cut it open) put new one on, and it ran perfect for 50 odd miles, now its back to same old self.

Even just pressing brake pedal enough to put brake lights on cause engine to shake, even intermitent wipers setting.

Now If i unplug the smart charge plug on alternator, things seem to be better, not perfect but a touch better.

Fords charged me £78 to scan it, and then said no faults found .

I would really appreciate your help and advice.
If you require me to do any testing of vehicle, just ask me, and I will post up results.

Thanks in advance.