[jtp7571]

can't do a FAQ search. I am trying to hook up the back up light to my horse trailer but there seems to be a problem. You see I have a plug that allows me to plug the existing 4 pin into it and then all I had to do was hook up the blue wire to the electric bakes, the black wire to the battery and the white wire to the ground. Well it seem to me that hooking up the big wire to the ground is by passing the one that already exists in the 4 pin. Is this the case and does anyone have any suggestions?