Thanks to those that responded, new sensor fitted after after applying some good old fashioned sleuthing and logic. The fitting instructions were not exactly clear (maybe to an experienced mechanic) but after tracing each connection and matching wire colours with the new fly lead the sensor was fitted and works fine. As R-III-R said above it was a bit fiddly and I could not route the new cable behind the frame because the airbox would not allow the connectors to pass through the gap between it and the motor so I routed the cable behind the side cover and outrigger cover. Funny how the diagrams in the instructions now look more sensible after fitting. Always learning! Thanks again.