Thanks again for the replies, Black sheep I cleaned in dynamo area with electrical cleaner, brushes seemed free, should they stand up above the holder mine were just level with housing ?
Bridged terminals together after removing ammeter which more or less fell apart on removal, insulated the joint and I have since done aprox 60ml with lights both on and off and battery staying charged so far. Found no other dodgy connections up to press either in headlight or under seat and regulator area.
So I am hoping ammeter was at fault and will now order another along with the rubber elbow connector between carb and airfilter box as that was noticed to be badly perished when cleaning filter .
Next question is ....the old one is black faced with no illumination on it , is that the standard one for 55 plunger GF A10 or would it have had a white face ?