4 Pin Flat Trailer Connector Diagram. Trailer Wiring Diagrams showing you the typical wiring for most single axle trailer and tandem axle trailers. One way to check for faulty wires is to use a circuit tester.
Cut the four-pin plug off of the trailer harness. In the North American market it is very common for brake lights and turn signals to be combined. Seven-pin connectors are rarely used on trailers for local use.
One way to check for faulty wires is to use a circuit tester.
Cut the four-pin plug off of the trailer harness.
Any vehicle towing a trailer requires trailer connector wiring to safely connect the taillights, turn signals, brake lights and other necessary electrical Connecting the wrong color wires will result in mismatched taillight functions and confusion on the road. Trailer Wiring Diagrams showing you the typical wiring for most single axle trailer and tandem axle trailers. In the North American market it is very common for brake lights and turn signals to be combined.