So many wires. So many colors. And, so many kinds of trailer wiring connectors. Where do I start? I need a trailer wiring diagram! And, a little more information to make sure I get all the wires right! There are several standards for go here wires, and if you search, you will find a different Trailer Wiring Diagram for each. The standards have a purpose, so there is no reason for kooky wiring that will not work with other tow vehicles.

The right wiring depends on your electrical needs. To start, every trailer needs lights — brake lights, turn signals, and tail lights. Some have electric for, and some need auxiliary power for interior lights, etc. The trailer wiring diagram s and explanations are a cross between an electrical schematic hookup wiring on a trailer. Then, below, there are notes for wire sizes and functions. This is the most common, and most consistent standard.

That means both wiring schemes will plug into the same tow vehicle and function just fine. Please see this other article for specifics of the RV Wiring Standard. The article also has a comparison chart if you need to convert or transpose. Other styles also exist — including industrial and military standards — with various styles of 4, 5, 6, 7, 8 pin connectors — and different wire arrangements. It can get confusing, so they are beyond our scope here.

If you do not already have a specific standard in mind, follow the trailer wiring diagram below. The most common 4 wire connection is this traditional 4-Pin Flat Connector. Trailers for this are usually fairly light weight and hookup brakes or other power accessories. For example, small utility trailers hookup, light boat trailers, little electrical, off-road trailers and many more will use this 4-Pin Flat connector.

The 4-Pin connector only has the first 4 trailer listed, then can ignore the other wires of the trailer wiring diagram. This 5-pin for similar to the 4-pin above, but not as common. Typically, the 5th wire blue is for Electric Trailer Brakesbut not always. Sometimes it is used for backup lights, or to interact with surge brakes, so be careful. The 5th pin is not as standard as the first 4. Trailers with capacity over Total Gross "Trailer" Weight should have brakes. That is not mandatory everywhere, but it is definitely a good idea.

If a trailer has brakes, then it needs a connector electrical at least 5 wires. See Blue Wire Notes below.

Equipping Your Vehicle with Proper Trailer Wiring

While the most common use of the blue wire is for electric brakes, the 5th pin is sometimes used to disable hydraulic surge brakes in reverseor for backup lights. Check it before connecting one. Note: If your vehicle has a built-in 7-pin socket, but you only need 5 pins, then use a 7-pin connector anyway see belowand leave out the last 2 wires.

It accomplishes the same thing for 5 wires using a connector that is already compatible with your vehicle. It is perfectly fine to leave some pins vacant. For trailers that have a little more going on electrically, we recommend 7-pin connectors. The 2 added pins are typically for Auxiliary Power and Backup Lights. See Red Wire Notes below. Sometimes another color. This is trailer style we recommend. It is OK to leave a pin or two blank unused and unconnected.

For instance, looking at the trailer wiring diagram, if you want Auxiliary Power, but do not have backup lights, then just leave the purple wire out. A blank spot unconnected pin does not hurt anything. Colors in this article follow the SAE Standard for all connectors. However, for the 7-pin blade connector, there is also an RV Wiring Standard. Weird, because the connections are the same, they just scramble the colors.

The important thing is the connections, not the colors. The 2 above trailer wiring diagrams fit the needs of most trailers. The first image shows a single axle trailer, and the second, wiring for Tandem Axles. Only the blue electrical and white ground wires have more connections for the tandem. "Hookup," you can expand the same conditions also for triple axles.

Use only the needed wires, and ignore the others. For example, if you have a 4-Pin connector, just ignore the Blue, Red, and Purple wires. Or, if there is not a need for Auxiliary Powerjust leave it out. Perhaps the axles do not have brakes, then no need for that. Do not change pin numbers or wire positions if a function is not used — just leave the pin blank not connected. The above trailer wire diagrams do not show the triple set of marker lights central on the front and back. Some trailers need them, and some do not. For this has to do with trailer for.

Check local ordinances for requirements. Check legal requirements to see if they are required in your country or jurisdiction. Also, near the top in the back if taller than a certain amount. An amber 3 light set is required near the top in the front, if taller than a certain amount usually some amount over the height of the tow vehicle. Again, check regional requirements.

Typically the 3 center marker lights are at a high point on the trailer — like above the back doors for an hookup cargo trailer. They are fine on the back bumper of a flatbed trailer, even when the load is much higher. There are lots of extras in the laws like top corner markingsso find out what you need for your specific trailer. If you need the more marker lights, connect them on the Brown and White wires just like the side marker lights.

See the partial trailer wiring diagram. These do not require additional connections at the hitch, just more wiring within the trailer. These lights should be ON basically all the time.

In addition to the three center marker lights, most trailers over 80 click here width require reflectors just click for source reflective tape in alternating red and white on for sides and back.

There are a lot of regulations here for height, and GVWR, especially when trailers are longer than 20 ft. I am not sure about requirements outside of the USA. Check your local jurisdiction so you can mark and light your trailer properly. Reflectors and reflector types change by jurisdiction. To some, this is overkill, but electrical if it is, making it right can save you a ton of legal hassle and trouble. Many trailers are required to have a Breakaway Something how to find your spouse on a dating site congratulate on board.

Basically, this is a way of applying the trailer brakes if the trailer comes disconnected from the tow vehicle. If you have electric brakes or electric over hydraulic or some othersthen it will involve the trailer wiring.

Here is a partial wiring diagram to include your trailer breakaway system. Since there is a lot to discuss, we have an entire article about this web page kits with lots more information. In the meantime, use this diagram to guide trailer wiring of the system.

Superimpose this on the images above to see how it all comes together. The breakaway system usually trailer in, on, or under the front part of the trailer. The pin pull switch is near the hitch.

How to Hook Up Trailer Lights — Trailer Wiring Tips & Tricks

Again, please see the article about breakaway systems for a lot more information. Where do the wires go? Now that we have the trailer wiring diagram and some definition for connectors, where do the wires actually go?

Nestle the wires into and around the frame where practical for protection. We do recommend protecting the wires with a covering of some sort. The electrical is not in the trailer wiring diagram, but flexible conduit, plastic conduit, or other approaches are great.

A covering does not need to be watertight, but do consider weather protection when splicing into the wires. For tips on wiring, splicing, routing and protecting, see our post on trailer lights and wires. See more in the Wire Routing Notes below. This photo shows an ideal way to handle trailer wires. While the flexible sealed conduit nestles in and secures to the frame, it protects the wires from snags and from weather.