Charge light on faintly at low revs

[andyk]

Alternator drive belt has just been changed and now the charge light on the dash comes on faintly at low revs. Belt is on tight. Changed the voltage regulator / brushes only a few miles ago. Any ideas please?

[Aidan]

when this happened to me I discovered that the alternator bracket (petrol wbx) had cracked through the welds so the alternator's earth connection was poor to the block