6 Pin To 7 Pin Trailer Adapter Wiring Diagram (Helpful Guide)

There are many details when you are getting ready to tow. There is a tone of details to work out. One of those is making sure that all the electrical devices in your trailer work. This can be difficult when you are connecting a 6-pin adapter to 7 pin model. Not everything lines up.

There can be a lot of confusion when trying to connect a 6-pin trailer hook up to a 7-pin tow vehicle adapter. Not every model is built the same or has the same designs. usually, the AUX plug on the 7-pin side is the odd man out. Many 6-pin options are not built to the standard, just a standard, and that causes a lot of problems.

To learn more about this topic, just continue to read our article. It explores this topic so you have the information you need. Take a few minutes to see how this information helps you make the right connection between your tow vehicle and trailer.

Can You Use a 7-Way Plug With 6 Wires?

Can-You-Use-a --Way-Plug-With-6-Wires

This is a possibility and it is probably done all the time. There are many trailers built years ago that only have a 6-pin plug. These trailers are often towed by modern vehicles that were given 7-pin plugs.

The connection can be made, the only thing that should happen is that one pin on the 7-pin adapter will not work. There is no connection for it to send signals to. Also, before you make this connection, you should know all the functions of the pins on your trailer side.

This will help ease some problems when you find that something important is not getting any power. To know what each pin or wire for your trailer powers, hook up a 12-volt battery and test each one at a time. If the power to the green wire lights up your right brake light and turn signal, then you know what that green wire does.

What is The Difference Between a 6-Pin And 7-Pin Trailer Connector?

According to our research, the only difference between these two plugs is that the 6-pin model does not have a pin for the back up lights. The 7-pin model will. If this is a problem or not depends on the laws in your state.

If your state has no problem with your trailer being without back up lights, then all you need is the right adapter to make the connection. To find the right adapter, just go to your local hardware store, a big-box outlet that carries this part, or Amazon, etc., and buy the one that fits your 6 and 7-pin plugs.

The cost of these adapters will vary depending on where you are buying them. RV parts and accessory stores should have some type of supply of these adapters. If you are not sure, take a photo with your phone camera and show the clerk what you need.

6 Pin Trailer Plug vs 7 Pin


The 6-pin model does have its uses. But the only real problem that we have found is that you may not get all of your trailer functions, lights, etc., working. The 7-pin model has an extra pin that makes sure that the back up lights on your trailer turn on when you put your tow vehicle in reverse.

The center pin is usually for the yellow wire but it is the AUX pin that could power just about anything. Usually, it is the trailer’s back up lights. This is okay if your state does not require that your trailer have back up lights.

The way the 7-pin is marked is as follows- 1 White = Ground

2 Blue = Brake

3 Green = Running Lights

4 Black = 12v+

5 Red = Left Turn

6 Brown = Right Turn

The 7th isn't marked but is the center terminal

What is The Black Wire on a 7-Pin Trailer Plug?

The chart given above shows that the black wire is the #4 pin and it is for the 12-volt power supply. The positioning may not always be clear but it should be the pin at 11 o’clock on the plug.

Keep in mind that the pins do not go in numerical order (1,2,3, 4,5,6, 7). They tend to be mixed up a bit with the #3 and 4 pin at 1 and 11 o’clock respectively; the #1 & 2 pins at 5 & 7 o’clock respectively; and the #5 & 6 pins at 3 and 9 o’clock respectively. At least on one of the wiring diagrams, we will link to later on.

Of course, this positioning depends on how you hold the plug and is used to add a little clarity to the topic.

What is The Color Code For Trailer Wires?


There are 6 colors used for trailers. The first color will be brown. This wire powers the tail or parking lights. The black is the power or hot wire and the white-colored wire is for ground

The green wire goes to the right brake light and turn signal. Then the yellow wire should power the left brake light and turn signal. That leaves the blue wire. This wire operates the brake controller output.

It is a fairly simple system to understand and when you are making connections, you just need to line up the different colored wires in the same order and you should be fine.

The only thing you have to watch out for is if the adapter or plug makers switch colors on you. This is the case with the 7-pin RV plug and the 7-pin utility plug. You should double-check when you are buying parts that the wires match up with what you already have on your trailer and plug.

How do You Wire a 7-Pin Trailer Plug?

For the most part, you need to match a color wire with like-colored wire. For example, for the brakes to work, you need to match both blue-colored wires and connect them.

There are different wiring instructions for different types of brakes on your trailer. When it comes to electric brakes, you have to use the same blue wire for both sides. That means you have to splice the blue wire into two parts. You run one wire to the axle, then splice it into two wires.

One blue wire is connected to the terminal of the coil on the electromagnetic brakes. The second blue wire is supposed to be connected to the white ground wire. You also want to connect the white wire to the brakes not the metal frame of the trailer.

When it comes to hydraulic brakes, you do not need to connect the blue wires to the brakes. In fact, you do not need the blue wire at all. Just leave it unattached to avoid any confusion later on.

There is no need to connect the blue wire to any other function. It is safe to leave unattached and not power anything. To read these instructions and other wiring connections, just click on this link. It has a lot of wiring instructions that cannot be put here.

6 Pin To 7 Pin Trailer Adapter Wiring Diagram


There are several websites on the internet that have different wiring diagrams. they all seem to be the same except for how they are presented. The first one is found at this link. There are a bunch of different diagrams on this website and to get to them, you just scroll down.

Another website you can use would be at this link. It comes with similar drawings as the previous link. Finally, click here to get to the last web page we will use in this section. Some magnification may be needed to see the wiring diagrams clearly.

How To Protect Wires For a 7-Pin Setup

Here are some tips to help you keep those wires safe when you have to run them a long way.

1. Tie the wires to the trailer frame to keep them in place. Some plastic ties would be the best things to use.

2. Use plastic conduits or those made from non-conductive materials to hold the wires. Use junction boxes where you made your splices.

3. Or you can use regular electrician’s tape, insulation, braids, or PVC pipes. Also, wire hangers or clips will work well.

Some Final Words

The key to connecting a 6-pin plug to a 7-pin plug is finding the adapter. You have to be careful though as 7-pin models have flat and round pins while the 6-pin model has round pins only.

It is safe to make this connection as long as you do it right. All that you lose is one function wire and that may not be necessary to have anyways. Check your local stores for top-quality adapters.

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