Abstract: A system is disclosed herein for advising an operator of a towing vehicle of the relative angular position of a towed load such as a trailer with respect to the longitudinal centerline of the towing vehicle. The system includes a trailer tongue and ball hitch coupling device for interconnecting the towing vehicle with the trailer. The coupling device includes a rotary sensor for determining angular displacement of the trailer tongue with respect to the ball hitch and an electrical wiper arm device for converting the mechanically sensed displacement into an electrical signal for application to an operator warning indicator mounted on the dashboard. The indicator has a visual display of the relative angular position of the trailer with respect to the towing vehicle and further includes a dynamic indication of whether the angular relationship is increasing or decreasing.