hello all, just before xmas i asked how to wire up my alternator, as it was slightly different fitting to the previous one. fitted it fine but its not charging the battery......

pic...



i have wired it up as advised by a few on here and by how the shop owner tells me. but no joy.

what is the black box thing circled in green in the pic? is this needed? mine hasnt got one. i have one of these on my old alternator that i could maybe transfer over. could this be the prob? cheers