Originally Posted by
Trevhib
Have you got a multimeter? You need to test to see if the alternator is charging the battery by setting the meter to 20v and putting the red/black leads on the positive and negative terminals and having a look.
If it isn't charging then I'd look at all the alternator connections, remove, check, clean, replace and re-test.
I'd then do the same with the main earth points on the engine. Actually if the alternator looks to be ok you could just have an earthing problem.
That's not a bad price for an alternator though I imagine that will be a reconditioned one.