How to Wire a Flat Deck Trailer

Trailers are made in different styles and for different purposes, but the type that allows for the largest variety of loads is a flat deck trailer. A flat trailer is easy to work with, as it can handle all kinds of loads. No matter the shape or size, you can move any item as long as you properly secure it to the trailer. Loading and unloading various kinds of items is even easier since there is nothing on the sides of the trailer.

Flat Deck Trailer


Wider loads are easy to haul, as well as complex loads that have an awkward shape and are very heavy. If you’re not keen on towing around the same loads and like to have the option to work with different cargo every single time, then a flat deck trailer is the right option for you. But before you tow a trailer, you need to set it up the right way and the same goes for flat trailers.

How to Wire a Flat Trailer Plug

1. The first thing you need to do when wiring a flat trailer plug is to prepare by having all the necessary tools at hand to hook things up. These mainly include a crimper, needle nose pliers and a tester screwdriver. Some flat deck trailers require you to remove either one or more lights.

2. Once you have everything you need, start by connecting the ground wire to the trailer frame. The white ground wire needs to be attached directly to a bare and clean section of the frame with a self-tapping screw, as well as a ring terminal. Make sure to ground each trailer light separately along the trailer frame. This will reduce the risk of a ground issue in one component which has an impact on the whole system.

3. Next, you’ll need to run the rest of the wires along the frame of the trailer, all the way to the taillights. Do not let the wires chafe or catch against the trailer’s components. Feed the wires through the hollow parts of the frame for better protection.

4. When it comes to making the connections, you’ll need to use a crimping tool to strip the insulation from the end of each wire. You’ll also use butt connectors to connect the wires as well as a heat gun. Every light will need to have 3 wires connected to it. Usually, the green wire is for the right turn/brakes, the brown wire is for the taillights, white is obviously ground and the yellow wire is for the left turn/brakes. This is a classic 4-pin wiring diagram, but some flat deck trailers utilise a 5, 6 or even a 7-pin diagram. Make sure to take a look at the manufacturer’s website or manual to figure out the setup on your flat deck trailer.

Flat Deck Trailer


What Makes a Good Flat Deck Trailer


The size of the trailer will determine how big of a load you will be able to tow. But the size of the trailer you can tow is going to be limited by the size of your vehicle. The bigger your vehicle, the bigger the trailer you’ll be able to tow. This doesn’t mean you should get the biggest trailer your vehicle can tow, though.

Load Capacity

Another important feature of a flat deck trailer is its load capacity. This is also limited by the vehicle. Your vehicle’s load-carrying capacity is going to determine the load capacity of the trailer, since both the weight and load capacity of the trailer shouldn’t exceed the load-carrying capacity of your vehicle. The load-carrying capacity of your vehicle is labelled as GVWR which is found on the driver-side door sill or in the owner’s manual.


Just like you need to get a trailer with adequate load capacity, you also need to get a trailer that comes with the right configuration of axles. This will be determined by the local laws in place, as some will require you to have an axle configuration that supports only the weight of the cargo and some that support both the wheel assembly and cargo.

Flat Deck Trailer



While the tyres of a flat trailer may not seem as important as the size and load capacity of the trailer, they are, simply because they are the only component that is in contact with the road. Make sure they are always made for the road conditions you’ll be driving in, and that they are filled up adequately.


Something that we take for granted today and which seems to be less of a concern is durability. Not only can durable flat trailers handle a heavy load but also do so for a long time without falling on you. A durable trailer will also retain a higher resale value than the majority of more affordable trailers. This means if you do need to get a better trailer than your current one, you can get good money from the old trailer and thus, spend less on a new and better one. This is a win-win situation even in the long run.