electrical connector guide

Know-How Notes – Wiring Terminal & Connector Guide

So you finally got that pesky intermittent electrical problem on your ride traced down to a bad connection. Now you just need to cut it out and replace it, but with what? There are all kinds of electrical terminals out there; figuring out exactly what you need can be confusing. This Know-How Notes will focus on the different types of wiring terminals and how to choose which one you need.

For the purposes of this article, we are only concerned with the typical connectors that are used by themselves, we are not looking at specialty connectors like Weather Pack or Metri-Pack, or anything of that sort, just the basic wiring terminal you can find at your local NAPA parts store.

When choosing a wiring terminal, you need to remember that there is a correct size for every wire gauge and a correct crimping die to match. Insulated terminals are selected by a range of sizes noted by the color of the insulation. Any wire larger than 10-gauge requires a non-insulated terminal. These terminals usually come with a slip-on silicone insulating sleeve, but not always.

Red- 22 to 16 gauge

Blue- 16-14 gauge

Yellow- 12-10 gauge

All terminals are wire-gauge specific. The smaller terminals use yellow, blue, red color codes, where the larger gauges do not.

All terminals are wire-gauge specific. The smaller terminals use yellow, blue, red color codes, where the larger gauges do not.

 

Spade Type – Also referred to as disconnects, spade terminals are the most common electrical terminal you will find on a car. There are three types- male, female, and fork. Spades are most often used to connect wires to relays and components. They come in different widths, but most use the common standard size.

Male – This is the blade side. Male blade terminals are used to connect to female spades, T-taps, and can sometimes be used to replace a specialty plug in a pinch.

Female – This is the socket side. This is the most common connector you will use to connect wires to components.

Fork – Forked spades are used to connect wires to components that use a clamping hold down. They can be replaced in many cases with ring terminals, but for installation ease, the fork allows the wires to be installed or removed quickly.

Ring – The ring terminal is used almost exclusively for ground connections, but larger ring terminals are used for battery connections. In some cases, you can swap a ring terminal for a forked spade.

These the most common spade terminals, in male and female. These can connect to components or each other, making them quite versatile.

These the most common spade terminals, in male and female. These can connect to components or each other, making them quite versatile.

 

These terminals are fork (top) and a ring (bottom). There are different sizes in the width of the fork and diameter of the ring. Make sure you have an assortment.

These terminals are fork (top) and a ring (bottom). There are different sizes in the width of the fork and diameter of the ring. Make sure you have an assortment.

 

Barrel – These terminals are intended for wire to wire connections. When a wire gets pinched or broken, you usually can’t just run an entirely new wire, you have to splice it. These are your go-to terminals for that.

Butt – This is the main wire to wire splice connector that you should use. Butt splices have a crimp terminal on either end. One wire goes into one side; another wire goes into the other side. This keeps the wires running in a continuous line, making it easier to secure and bundle with other wires.

Cap – Also referred to as “crimp caps”, these are a common connector used in stereo installations. They are functional and work well, but they only have one hole for the wires, so if you use this to make a splice, then the wires will make a 90-degree turn in and out of the connector, which doesn’t work well for wrapping up the wires in a loom. They do serve a purpose and make good connections. When using crimp caps, twist the wires together before inserting them into the cap and crimping.

Caps and butt connectors are used to connect two wires together, these work great for fixing broken wires.

Caps and butt connectors are used to connect two wires together, these work great for fixing broken wires.

Bullet Connectors – These are quick-connects similar to spade terminals, but with a round barrel design. These are less common, but found in older cars as factory connectors. You can use these in place of spade terminals, but be aware that they are not as easy to find and harder to connect and disconnect that spades. It is very easy to accidentally pull the wire out of the terminal when trying to separate a barrel connector. These come in male and female halves.

Bullet connectors are not used much these days, but older vehicles, especially Ford and Mercury, used these for everything. They are hard to find and even harder to get apart.

Bullet connectors are not used much these days, but older vehicles, especially Ford and Mercury, used these for everything. They are hard to find and even harder to get apart.

Taps – Sometimes you don’t need to splice or make a new connection, but you do need to grab power or a trigger from another wire. That is where taps come into play. Modern cars are often more difficult to find free 12-volt sources, so tapping into another source is required.

T-taps – The best solution for tapping is the T-tap. This style uses a metal connector inside a plastic housing that when closed, cuts the insulation of the wire being tapped and then a male spade terminal is used to complete the connection. T-taps make it easy to tap into a wire and remove it when needed.

 

T-Taps work really well when you use the removable version like this (center).

T-Taps work really well when you use the removable version like this (center).

Side-By-Side Tap  – The lesser version is the side-by-side tap. This is a permanent tap; the secondary wire is pinched at the same time as the main wire, and can only be removed by removing the tap. These are good for emergency repairs but they should not be used for a permanent repair.

Threaded – There are new styles quick connects that use threaded barrels with metal inserts to make the connections. These do not require tools to install, and are really good for roadside repairs. These terminals are usually more expensive.


It is always a good idea to have a few terminals of each size and type on hand in your vehicle. Electrical issues are always easier when you have the right parts and tools on hand. With this information, you should be able to get the job done without too much hassle.

 

To learn more about NAPA AutoCare, visit www.NAPAAutoCare.com.

about author

Jefferson Bryant

A life-long gearhead, Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 4 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced.

related articles

2 Comments

  • Earl Rusert

    July 22, 2016 at 6:01 AM

    Reply

    Good info. Thanks

  • Mike DeAng

    December 10, 2017 at 8:23 AM

    Reply

    Thanks, Jeff. Great info, just what I needed.

LEAVE A REPLY

Your email address will not be published. Required fields are marked *