I decided to look under my car today and I found a black wire hanging to the ground going from the front of the car all the way to the trunk. Normally black wire represent ground right but to what ? The car also has a uhaul hitch installed n in the trunk there's a wire to connect the lighting of a pull trailer I believe. Can this be for that wire ? I secured but its got me worried ? So many wire . Sensitive things I don't want to mess with.