Continue reading for more information on the remaining wires in a 7-pin trailer lights wiring diagram. The brake lights wire (colored red) carries the power required to operate the trailer's brake lights. When the towing vehicle's brakes are applied, this wire activates the brake lights on the trailer, alerting drivers behind.. Your standard trailer generally only has 5 wires and the 2 spare pins (pins 2 & 5) are generally for electric brakes or caravan accessories. 7 PIN FLAT 7 Pin Flat / square plugs (American Style) are great for newer vehicles and follow the same 1-7 numbering system as the 7 Pin Round plugs.
All diagrams are as viewed from the Cable Side . Small 7 Pin Round (QLD) Identifying: Plug size is similar to an Australian 10c coin. There is a noticeably larger gap between 1 and 6 on this plug, though some trailer places rotate this connector that the yellow is at the top. Socket and plug are keyed. All diagrams are as viewed from the Cable Side. If you need a 4 wire trailer light wiring diagram, follow the first 4 wire colors. If you need a 5 wire trailer light wiring diagram, follow the first 5 wire colors. The 7 wire trailer light wiring diagram is, of course, all of them, but you don't have to use them all. It is OK to leave wires out if you do not need the function.