When towing a trailer or a truck, electrical connectors ensure that your trailer’s lights, brakes, and other electrical components function properly. Various types of towing electrical connectors are available, and selecting the proper one for your towing needs can be overwhelming.

The most common types include 4-pin flat, 4-pin round, 5-pin flat, 5-pin round, 6-pin round and 6-pin square connectors. Each type offers different configurations and capabilities to suit your specific towing needs.

 7 Types of Towing Electrical Connectors

When towing, several different types of electrical connectors are available. These include:

• 4-pin flat trailer electrical connectors

• 4-pin round trailer electrical connectors

• 5-pin flat trailer electrical connectors

• 5-pin round trailer electrical connectors

• 6-pin round trailer electrical connectors

• 6-pin square trailer electrical connectors

• 7-pin round trailer electrical connectors

 4 Pin Flat Trailer Electrical Connectors

If you have a small utility trailer, tow truck, or camper that doesn’t require brakes, you can use a 4-pin flat trailer electrical connector for basic lighting functions. This type of connector is commonly found on these vehicles and allows for a simple connection of the three essential lighting functions.

• White for ground wiring,

• Brown for running lights,

• Yellow for the left turn indicator and brakes, and

• Green indicates right turn and brakes.

4 Pin Round Trailer Electrical Connectors

The 4-Pin Round Trailer Electrical Connector is a professional and informative solution if you’re looking for a reliable and secure connection. If you’re using a heavy-duty 4-way connector with a 35 amp rating, remember it has a larger ground pin and won’t mate with the standard 20 amp version.

• White for ground,

• Brown for running and brake lights,

• Yellow for the left turn signal, and

• Green for right turn signal.

5 Pin Flat Trailer Electrical Connectors

The 5-pin flat trailer electrical connector is commonly found on utility trailers, medium towing trucks, and campers with brakes. While it may be considered a temporary setup due to its potential for easy disconnection or corrosion, it allows for a basic running connection.

• White indicates ground,

• Brown represents running lights,

• Yellow indicating left turn indicators and brakes,

• Green represents the right turn indicator and brakes, and

• blue indicating electric brakes.

5 Pin Round Trailer Electrical Connectors

You can easily identify the 5 pin round trailer electrical connectors by their unique wiring code and an additional wire for reversing brakes.

The wiring code for these connectors is as follows:

• The white colored wire is for the ground,

• The brown wire is for running lights,

• The yellow wire is for left turn indicators and brakes,

• The green wire goes to the right turn and brakes and

• The blue wire is for electric brakes.

 6 Pin Round Trailer Electrical Connectors

A 6-pin round trailer electrical connector is a great way to connect the electrical systems of your towing vehicle and trailer. These connectors provide the necessary connections for the three basic lighting functions:

• The white colored wire is used for ground,

• The brown wire is for running lights,

• The yellow wire is for the left turn light and brakes,

• Right turn lights and brakes are on the green wire,

• The blue wire is for electric brakes and

• The black wire is for 12v power.

6 Pin Square Trailer Electrical Connectors

When using the 6-pin square trailer electrical connectors, match the correct wire colors for each function. This connector type is commonly used in trailers and requires a specific wiring code to ensure proper functionality.

• Ground is the white wire,

• Running lights use brown wire,

• The left turn arrow and brakes are on the yellow wire,

• Green wire controls the right turn and brakes,

• Blue wires are for electric brakes and

• The black wire provides 12v power.

7 Pin Round Trailer Electrical Connectors

Typically found on older vehicles and heavy-duty towing trailers, 7-pin round-pin trailer connectors are less common than flat-pin connectors. These connectors provide a secure and reliable electrical connection between the towing vehicle and the trailer.

• The white pin is for the ground,

• The brown pin is for the running lights,

• The yellow pin controls the left turn and brakes,

• The green pin is for the right turn sign and brakes,

• The blue pin is for electric brakes,

• The black pin is for 12v power and

• The orange or red pin is for auxiliary or backup lights.

How Do I Choose the Right Towing Electrical Connector

To choose the right towing electrical connector, consider several factors.

1. Consider Your Current Rating and Operating Voltage

When selecting electrical cable connectors, consider your operating voltage and current rating. The current rating determines how much current can flow through the connector without damaging or overheating it. It’s usually measured in amps and should be based on the maximum current you expect.

 2. Verify the Recommended Operating Temperature Range

Electric connectors designed for hazardous environments and extreme conditions incorporate special features that enable them to resist vibration, shocks, and extreme temperatures. These connectors are built to withstand the toughest conditions without compromising performance or safety.

3. Make Sure it has Environmental Sealing

Effective environmental sealing is crucial to prevent the entry of gasses, vapors, dust, or liquids that could ignite or cause damage. When selecting a connector, consider its protection level against unexpected splashes or exposure to hazardous substances.

4. Confirm the Level of Reliability

Reliability is crucial when selecting an electric connector, as it determines its ability to perform its intended function without failure consistently. To make an informed decision, check the reliability level of the electric connector you’re considering.

• Examine the connector’s construction and materials used. High-quality connectors are usually made from durable materials that withstand various environmental conditions. If you have towing mirrors on both sides of your vehicle, you must ensure that the connector you choose is compatible with them.

• Also, consider the connector’s track record and reputation in the industry. Reliable connectors are often backed by reliable manufacturers who have a history of producing dependable products.

What is the most common towing electrical connector?

The most common towing electrical plug is the 7-pin trailer connector. This connector is widely used in basic flatbed towing scenarios. Therefore, no additional auto electrical accessories besides the brake/tail and indicator lights are required.

Choose a Proper Towing Electrical Connector According to Your Vehicle Needs

Understanding the different styles of towing electrical connectors is crucial when selecting the right one for your towing needs. Factors such as vehicle compatibility, towing capacity, and wiring requirements should be considered.