I am trying to fit a 4 set of reverse sensors to a C4 GP and I have found that the wiring seems to be Can Bus type. The rear light cluster has a reversing light but I get only .5 of a volt when reverse is selected. There is 5 wire loom ( 4 positives and a earth) running the 4 rear lights. Has anyone fitted these type of sensor to a 2010 model. I tried using it with the wires connected both reverse lights come on but no power seems to go to the control box of the sensors. Any help would be welcome