Thanks for the replies everyone. It is working . Old Tony you are a legend, you had It right all along. I had the plug behind the grill so I assumed it was wired in but after ripping the cluster out and checking that wasn't the case. So here is what I did. I carefully cut the front plug up and removed the 4 connectors, I soldered 2 onto a 2 core wire and pushed them into the back of the cluster plug pins 49 and 50 then I used the other 2 connectors on the other end of the wire which I ran to behind the grill and plugged in the sensor. It currently reads 0.4c above the official BOM temps. Mine is a 2008 R51 yd25 for anyone doing this in the future. Thanks again guys