battery light problems

[a3emma]

done a bit of a search and cant seem to find anything matching my problem. ive got a 1.9tdi 110bhp a3. recently when i was driving the battery light came on and started flashing, and there was a slight squeaking noise as if the belt was slipping, and the Headlights went dim. this lasted for about 5 mins, then all of a sudden the light went out and the noise stopped. it done it quite a lot after that, but the last time it done it was about two/three week ago, and nothing has been done to the car. the battery and alternater has been tested and there all good. has anybody had anything like this happen to them before, or can anybody push me in the right direction?

 

[S3 TAM]

I'm having a stab in the dark here.

Might be your clutch on your alternator pulley that could cause the squeaking noise.

You can check the clutch by trying to move the alternator fan with a screwdriver it should move one way and not the other
if it doesnt move at all the clutch in the pulley is shot and needs replacing.