Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think The black battery wire should be same size as the white ground wire - 10 gauge in chart - faq311-7-way-trailer-diagram-rv_2_800 The picture below this chart shows correct wiring for RV plugs. As a professional RV transporter I have seen to many trucks wired with those 2 wires to small and cause a fire from overheating. Ford F-150/F-250: How to Replace Your Dipstick Tube Sep 19, 2014This article applies to the F-150 (2004-2014) and the F-250, F-350 Super Duty (2005-2014). Replacing the dipstick tube typically goes one of two ways: It will will either be relatively easy or a significant challenge to your mechanical ability, inventiveness, problem solving skills and most certainly your patience.