[fluff164]

Hopefully someone can help,

I recently started to hear a small whirring noise between 2000 and 300 revs in my 2.0 zetec focus. Within a few days, my traction control light started to flicker and basically the battery died. I naturally assumed the issue was the alternator, so charged the battery to give me enough power to get the car to the garage.

However!

Using a tester, we saw that the amps going into the battery were more than enough to charge the battery, so I puit on a new battery and when testing again, 14 volts were showin when the engine was revved. The issue here though is that when ticking over the lights are dull, but when I rev they do not brighten at all and my battery is now almost drained again! For some reason the alternator is putting out a charge, but this is not transferring. Can anyone help please?

 

[FocusMachOne]

That whirring noise your hearing is your alternator.

your alternator is bad. your diodes are more then likely shot.
the whirring noise is AC current backfeeding through your rectifier.
now granted that noise should sound more like a high pitched growling, but i assume thats what you mean.