Fan belt or alternator??

[jock23]

Since getting my fan belt replaced a few months ago, the car has been making that horrible schreeching noise when accelerating sometimes and in idle (especially in wet/cold weather)

I presumed it was the fan belt slipping so had a go at tightening it (with the nuts above the belt) but it doesnt seem to have worked.

Is there anything else that might be causing it? I remember when it got replaced that one of the rubber bearings broke and I had to get a replacement from vauxhall. Could it be this?? How can I tell what it will be?

[mowgli]

how much adjustment is left on the alt.?
could be alt. bearings, or fan belt, or oil leak causing slippage, or even timing belt cover could be loose

[Adam]

Start the car without the alternator belt on, this will make sure its the belt thats screeching.
Whilst the belt is off, turn the alternator pulley by hand, it should spin nice and freely, if it feels rough and makes clicking sonnds then the bearings are going.
The pulleys might have glazed over slightly, use some fine wet and dry to roughen the surface slightly to help the belt grip.

Tighten the belt until there is about 10mm of deflection when pressing down the middle of the belt.