I need help with wiring my motor trike to hook up my trailer. Where do I connect the relay sub harness? A friend says it is inside the trunk lid on the bike, but that does not seem right to me. Will I be able to get to it by removing the seat, or just where do I plug in the sub harness? I have the sub harness and the isolator harness. :? Help, I know you trikers know how to do this.