Round 4 Pin Trailer Wiring Harness Diagram. September 20 2020. The image below shows the connector from the back side where the 4 wires are attached with screws.
To solve issues for a tow vehicle wiring that is different from my trailer for instance when a friend wants to borrow it i simply have a short adapter that connects the 5 pin harness to a 4 pin vehicle and the trailer goes without brakes. Most of the time the 4 way connector is wired as follows. It shows the components of the circuit as simplified shapes and the capacity and signal friends amongst the devices.
The image below shows the connector from the back side where the 4 wires are attached with screws.
White pin to your floor. You must check the trailer manual to see if the wiring is correct but normally the white wire is called the ground wire while the brown wire is used for tail lights. Find your round 4 pin trailer wiring diagram here for round 4 pin trailer wiring diagram and you can print out. 4 way round connectors are commonly sold without the wires although complete kits are available.