Tractor Trailer Light Wiring Diagram. There are several standards for trailer wires, and if you search, you'll find a different Trailer Wiring Diagram for each. This color trailer wiring diagram will help you when you need to connect your trailer to your truck's wiring harness or repair a wire that isn't working.
In the North American market it is very common for brake lights and turn signals to be combined. Check the wire harness for cuts. Next, test your vehicle wiring plug to make sure it is working.
Next, test your vehicle wiring plug to make sure it is working.
But wiring a trailer may not be easy.
I hooked up one of the Uhaul harnesses to my ML. To do so, you will need to check the connector and wiring from the vehicle to the trailer. Many trailer light wiring problems occur because the wires are not properly grounded.