Thanks Simon, I trawled the site a week or so back for that info, thanks for posting the link, makes finding the info again easy.
I've yet to pull the plate out from under the dash, been busy connecting up some rear vision wiring and cameras. Someone said the open plug could even be in the centre of the truck. I'm waiting for the ford connection plug to hook in so I don't have to cut into the existing wiring to connect the Redarc controller.