WARNING
- Safety chains, hitches, and couplers do not provide adequate grounding by themselves and can cause electrical failures.
- You must have the correct vehicle wiring when using your trailer. Trailers not equipped with brakes will have a 4-way flat plug and all other trailers will have a larger 7-way plug. Don’t forget that a ground wire running from the plug back to the frame of the tow vehicle must be incorporated into proper tow vehicle wiring. Below are diagrams of the 4-way and the 7-way plugs.