Panic sets in . I left it and went off to my allotment.
9 o'clock tonight I started on it with a heavy battery discharge tester. Good battery. Interior lights were flickering to indicate a very poor battery connection.
The + battery conection was 27 years of age which is kind of suspect and then I remembered I had a NEW complete one ( starter , alternator plus two spade connectors ) somewhere in a wooden shed.
I had seen it 2 years ago and found it after 10 minutes.
Fitted the whole lot and now everything works as it should with a multimeter reading of 14 volts.
So at this late hour , its