Well ! Thanks to Youtube, I fixed the problem. it appears that there's a two pin connector actually in the fuel tank. I removed the rear seat, lifted the plastic diaphragm, disconnected the two fuel lines, opened the locking ring, lifted the unit and cleaned the little connector. For someone who was on a voyage of discovery, it took from lifting seat to replacing seat just under an hour. No low fuel warning and no £££ to a garage. * Feeling smug* I hope it lasts.