Battery light on, battery not charging.

Just wondering if anyone has any ideas.
Since i got this golf the alternator light always used to stay on till i gave it a little rev,  then it went off.
The other day it wouldnt go off at all and now my battery is dead.

Checked the connections on the back,  look ok.
Cleaned the connections on the little earth wire.
 Light still wont turn off.

looks like the wires go to somewhere under the battery, is there anything under there worth checking?

Was told this is a new alternator and it certainly looks it. Might see if i can get it tested though.
Battery is new too.

Thanks in advance
Dom

Hi mate, mine had this problem a couple of weeks ago and had to fit a new alternator!
There is a check that i did that can help confirm if it is the alternator, there should be a blue wire from the alternator, this is connected to the warning lamp and if you can follow it back from the alternator it should go into a little connector just at the side of the battery, disconnect this and the warning lamp should go out,if it does then it is more than likely the alternator, if it stays on then its a different fault! It is possible to change the brushes in the alternator but there are so many different types its difficult to get the right ones, i tried 3 different types of brushes, all listed for my vehicle but none of them were right so opted for the alternator and she works a treat. You mentioned the battery lamp staying on until you rev the engine a little, i believe this is normal so dont worry if it still happens when a new alternator is fitted. Hope this helps?
Paul.

Yeah mine stays on till I give it a little rev, nothing to worry about. Hope you get the main problem solved.

Dan

check the voltage regulator/brush pack, it unscrews from the back. give the metal contacts on it a clean, theres a ring round one of the screw holes and a metal part on the front that touches some prongs on the inside. check the brushes look ok, if worn or uneven replace.

the battery light should go out as soon as the engine is running, if it requires a rev to switch off there is something wrong with your alternator

Right, this was an expensive one. Checked everything, including the voltage regulator pack. checked again , all looked fine.
I was getting obsessed about the wiring in case it was that, realised the alternator "loom" only has 3 wires and two go straight to the battery. Thanks to Goly i now know what the other one does. Im learning all the time

Finally got a new alternator, definately charging the battery good now

Only 2 slightly concerning things,

1.  The light does still stay on untill the revs are picked up slightly, could this be due to a low idle? (frightened me when i first started her up) lol

2. Got in it earlier and it was screeching like nothing, eventually it stopped and has not done it again.( didnt do it at first either) I may tighten the belt tomorrow but it felt about right to me..

Least she is ready for sunday

Oh and how rude of me, thanks a lot guys appreciate the help

1. if the base idle is too low then maybe, 900rpm is where I set them
2. if the belt is slipping check the tension, you want 5mm deflection. it will need rechecking after a few miles as the belt stretches a bit

if the belt keeps slippign then look at the pulleys, maybe one of them is stiff or worn smooth which will make the belt slip and in turn stop the alternator spinning up properly at times