I just ran a quick connect to the back of my dad's new Super Duty (I know it's a bad word on this site, but I have to admit it is a nice truck). I grounded the quick connect on the back to the hitch frame, and then I ran the hot lead all the way up front to the battery. The kit came with an 18" wire that says to ground the battery to the frame, or the engine to the frame (in case the engine is isolated from the frame by rubber mounts). Since it is a diesel, it has dual batteries. I wired the circuit breaker for the winch to the passenger side battery. From what I could see, the driver's side battery was grounded directly to the frame. The two batteries are run in a series (I didn't see an isolator between the two of them). Do I need to ground the passenger's side battery? (I forgot to look to see if it was directly grounded to the frame). If it is grounded to the frame am I fine without running the extra ground wire the kit came with? BTW, this is a superwinch S4000 utility winch. It is going in the front of my dad's 14' covered car trailer.