That usually does the trick ;-) Charging circuit is very simple - there are three wires from stator coils going in to regulator/rectifier supplying AC voltage, and two wires out supplying DC to the battery. You can wire the reg/rect up using patch wires and spade connectors to test that the reg/rect is working. If it's working using cables and spade connectors then there must be a break in the loom somewhere else causing malfunction. But try the swearing trick first :-)