T 4 Wire Trailer Wiring Diagram. 4 wire trailer wiring diagram the 7 pin trailer plug is used on leisure trailers and cars. Attach white ground wire to vehicle frame.
Wiring diagram for self switching relay on 12s socket. Brown pin for side markers tail lamps and running lights. Plug size is similar to an australian 10c coin.
Yellow and green are for left and right turns and braking.
7 pin flat the best. Trailer wiring diagrams 4 way systems 4 way flat molded connectors allow basic hookup for three lighting functions. Many trailer sockets have a live wire to operate the electric fridge in the trailer. They also provide a wire for a ground connection.