I have just purchased a Ford wiring harness for my new E350 van. Part of it bypasses the backup sensors, but the 4-pin white connector for the 7-way plug is there and I can't find where to plug it in! There is a block on the frame with a white 6-pin connector pluged into it, but I don't know what it is for, or if there is a block that is used to be a connector for the two plugs.. Maybe Ford sold me the wrong harness? Any ideas?