I wanted a backup warning light in the cab of my F250SD stick shift diesel. The trailer plug (Ford XL3T-14A624-BA) shows the center connector is for the trailer backup lights. The wire to that connector is black with a green stripe. Sure enough, that has
12VDC when I put the truck in reverse. The local Ford dealer showed me where the backup lamp relay coil was located under the hood (adjacent to the Power Distribution box, relay #38). Sure enough, from there was a black wire with green stripes that only had power when the truck was put in reverse. I then tapped that wire from where it passed under the cab to the trailer plug, and routed it to a clearance light I installed under the dash. This worked great in my test drive. However, after I shut off the truck, I found the truck parking lights lit, but with the light switch turned off! The only way I found to turn off the parking lights was to pull the fuse (#4 ("Trailer Tow Backup Lamps, Trailer Tow Park Lamps") in the Power Distribution Box under the hood). What is going on here? What has the parking lights turning on when I'm just tapping the trailer backup light source?? Some computer module sensing what I've done?E. Eugene Herbert
Does your State pay lawyers to sue it? Alabama does!