Just an update. It was still blacking out after I fixed it. So I did the hard work and took off the tank and checked things myself. The lo beam's ballast was placed flat under the tank on the flat metal surface where the oil tank rubber pipe comes out of the frame. I think the vibrations caused it to cut out?? Perhaps the plug cables were too tight causing them to pull out of connection?? I also swopped the ballasts then fitted them in their old place. I took it for a ride at night and it worked perfectly. No cut outs, no blackouts, only light. Now I am finally happy :-D