As i havent fitted mine yet i`m not 100% sure, but the wires should be one redand one yellow behind trim nearside boot trim. you should find them taped up to the wiring near to the 2 electrical boxes (fog lamp cut out and trailer light relay) fixed to the nearside rear corner. The part no i cant help you sorry, but if you speak to a Ford parts shop to look at the page with Kuga detachable towbar on it, on the right side it shows at the top the 2 electric boxes i refer to above, and belowthem a lead which is labelled 13 pin power supply. For a switchable relay check out Towsure and look for a Smartcom relay.Sorry but best i can do. Good luck. PERMANENT POWER FEED PIN 9 RED WIRE, SWITCHED POWER SUPPLY FOR CHARGING PIN 10 YELLOW WIRE.Edited by: BruceKuga