I pulled the rectifier off & found one mount had sheared. The insulation looked good, did not see any bare wire as Calum's photo. Disconnected the connector by the oil filter but 2 other wires go up to under the cowl either side at the front so remade those as well. Also pulled the plugs on the front lamps & found no bare wire. Remade the earth connection behind the rectifier.
On restarting voltage was 14.3 even at idle with head lamps on. My joy did not last long dropping back to 13.8V headlamps on & 14.4 on side lamps.
So I'm thinking maybe a failing rectifier. What Harley unit fits & do they have all the correct connectors including earths & the 2 wires up under cowl? If not do I need to buy connectors to solder on?

Tim