Wire Harness Connector Types: What Are Their Differences


Connectors are a critical component of cars because they form an easy connection between wires and the different electrical components of the vehicle. They help remove or attach wires to any element easily and quickly. One connector can connect up to 100 wires. Nowadays, connectors are waterproof, corrosion-proof, and offer good electrical connections for the vehicle’s long life. Today, we will study different wire harness connector types used in cars.

Table of Contents

What are Wire Harness Connectors?

Connectors help in joining two or more wires resulting in an easy connection. You can find them in a wide variety of styles and sizes. The main parts of the connector include:

The shell

The shell has a complicated shape that works as a locking clip to join two halves of the connector. You can find specific holes for the pins and the barbs to lock the pins in place after insertion. You can fit different things tightly as many grooves hold the seals.

Wire Harness Connector Types: The pins and sockets

The pins and sockets help carry electric current from one part of the connector to another. Manufacturing plugs and sockets are exact, so they fit together to form a reliable connection. However, the link is not tight enough to make the connecting and disconnecting cumbersome.

While connecting, you can crimp the pins to the wires through a crimping tool. One part of the pin wraps around the wire while the other attaches to the insulation, resulting in a very tight connection.

Wire Harness Connector Types: The pin/socket retainer

This plastic piece can slide from the forward-facing end into the connector. It helps form a reliable connection between pins and sockets, so they don’t turn loose.

The seals

Each connector has a rubber seal on one side through which you can be fed all the wires. The seal fits firmly to the back side of the connector. Once you lock the connectors together, it is essential to prevent the ingress of moisture into it, and that’s what the seal does.

automotive male and female connectors

Caption: automotive male and female connectors

Wire harness connector types

Connectors are designed according to their performance requirement, and their functioning decides their ease of connection, durability, required insulation between pins, mating type, and various other features. All these features are designed to protect from harsh environments like constant vibration, moisture, dust, dirt, extreme temperatures, etc.

A Group

A group belongs to the power connectors that help connect an automobile’s head unit to the volume controls, electrical power supply, switches, and particular components such as antennas.

Wire Harness Connector Types: B Group

With these electrical connectors, you can connect your car’s speakers.

C Group

This group belongs to the surplus connectors that connect particular peripheral components such as remote controls, CD decks, and external amplifiers.

Wire Harness Connector Types: D Group

You can use these optional connectors to connect satellite navigation systems.

Multi-pin sealed connectors

These connectors help prevent the entry of various environmental factors.

Terminal connectors

With these connectors, you can make unsoldered connections.

Wire-to-board connectors

You can connect different components to the computer circuit board with these connectors.

Wire Harness Connector Types: Board-to-board connectors

These connectors link two different circuit boards.

Wire-to-wire electrical connectors

You can use these connectors for wire terminated cables.

Seamless connectors

They belong to the category of crimp-style automotive electrical connectors. These are made by cutting from the round stock; thus, they look like a tube.

Wire Harness Connector Types: Seam Type connectors

Unlike seamless connectors, these connectors are made by cutting flat stock. They take the form of a tube after rolling and have a seam that runs through the entire wire connection length.

Non-insulated connectors

As the name clears, these connectors lack insulation. Therefore, after crimping, it is essential to insulate them with heat shrink tubing with the help of a staking-type tool.

Insulated connectors

You can find these connectors in different shapes and sizes. These are either flared or straight towards the ends. Thus, these connectors must fit the wire’s and gauge’s outer insulation diameter.

Heat shrinkable insulated electrical connectors

These are the best automotive electrical connectors, and thus they are expensive too. As they are waterproof, you can use them for marine applications also.

Wire Harness Connector Types: AWG distribution type connectors

These AWG distribution-type connectors are giant and capable of handling high currents. However, if you work with enormous cables for charging systems, you need extra electric tools like crimp tools, cable cutters, distribution blocks, battery clamps, and a gas torch.

These connectors are available in up to 4/0 AWG and are suitable for all automotive applications with a high current rating. You can also use them to connect battery packs on forklifts. It would be best if you crimped the ends of these connectors as they are same-sex, i.e., their (+) and (-) go the same way. So, you have to be careful and should not make mistakes while connecting.

In race cars, you can use AWG wire 8 connectors to make a fast connection between the charger and the battery.

All the automotive connectors of road vehicles and passenger cars must follow ISO specifications during their manufacturing, testing, and installation.

illustration of an automotive connector

Caption: illustration of an automotive connector

Common Issues in Wire Harness Connectors

The high-quality connectors for your wiring harness ensure that their function matches their design. However, manufacturers face some common issues in the connectors when developers do not know the exact functioning of the connectors.


The most common issue that you may face in wire harness connectors is the contacts. Small metal pins or tiny parts form an electric connection on touching. If there is poor protection in the connector, contacts can corrode, affecting the electricity flow. Also, connector contacts have a limited lifespan. If the connection in your connector does not have the required number of mating cycles, it can lose its springiness with time and fail permanently.

Wire Harness Connector Types: Crimping

In crimping, you use a unique tool that creates a gas-tight joint between the two parts of the connector. Many wiring harnesses use the crimping technique to join wires to terminals or connectors. However, if you do not use the proper design or do not do crimping correctly, there will be loose crimps, which allow moisture penetration that finally results in corrosion. As a result, short circuits, open circuits, or complete electrical failure are possible.

Wire Harness Connector Types: Strain relief

With low-quality wiring harness connectors, you can face a common issue of strain relief. It is mainly a design feature with which you can transfer the force in any direction to ensure that it makes a solid mechanical connection. If your connector lacks desired strain relief required for the application, the wires can pull apart from the adjoining terminals.


Connectors use an overmolding material in their manufacturing, and the type of this overmolding material significantly decides the life span of your wiring harness system. You must pick material based on the application’s environmental condition and mechanical demands.

a bundle of crimped cables

Caption: a bundle of crimped cables


Connectors have signal contacts, power contacts, or different configurations such as wire to wire, board to wire, etc. The varied manufacturing of connectors results in a vast catalog of standard designs like 2, 3, and 4-pin connectors, weather-resistant connectors, same conductor locking connectors, etc. Based on your needs, you can choose custom connectors to fit the specifications of your applications. At Cloom, you can find a wide range of wiring harness connectors, harnesses, and cable assemblies for your specific use.