Fundamentals of Automotive Electrical Connections and Connectors

In my opinion, this is the single most important chapter of this book. Nothing is more telling of your wiring skill than the quality and integrity of your connections. In addition, your connectivity makes or breaks the reliability of the circuit you’re adding, adding to, or repairing. If there is something that I’m overly picky about, this is it. Best of all, these skills are easy to learn and implement.

 


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CAUTION: Obviously, making connections involves removing insulation from the wiring to do so. It goes without saying that you should not attempt to make connections to live circuits because you run the risk of shorting them in the connection making process. All of the methods in this chapter are written with the assumption that you are not connecting to a live circuit—turn it off before connecting to it!

 

Basic Connections

Basic connections are to wiring what knots are to rope. These are any connection between two wires that do not rely on a special connector or tool to establish. If you’re at home in the comfort of your garage and walk-in-sized tool box, you’ll typically elect to do things a better way. If you’re on the side of the road making a quick repair, you need to know how to do it properly. Generally speaking, these types of connections are fine for circuits with 5 amps or less flowing through them and for wiring of 16 -gauge or smaller.

 

Twisting and Taping

Of the million different ways to make this rudimentary type of connection, I’ve only ever seen one that could stand the test of time. Now, before showing you how to do it, I have to give some credit to the person who showed me how to do it this way:  B.J. Latting. He owns a business in Little Rock, Arkansas, called Arkansas Car Stereo. B.J. insists that this is the only way his staff can make these types of connections.

Here’s the right way to do it:

Step 1:

Grab two pieces of 18-gauge wire and strip 3/4 inch of insulation from the ends of each wire.

Step 2:

1Hold the two wires so that the bare wires cross at an angle.

 
 

Step 3:

2Twist the two wires tightly together in a clockwise direction.

 
 
 
 

Step 4:

3Bend the twisted connection into a U-shape.

 
 
 
 

Step 5:

4Lay the U-shape connection over one of the wires.

 

Step 6:

5Tightly insulate the connection with Super 33+ tape.

 

The first time B.J. showed me this, he also showed me the strength of the connection by having me attempt to pull it apart by the wires. When properly done, the connection will not break. Rather, you will tear the wire in half. Go ahead, try it and see for yourself.

 

The Westinghouse Split

This connection is implemented when you need to tap into a wire without breaking it and don’t have a soldering iron handy. Properly executed, this connection also stands the test of time. Here’s the right way to do it:

Step 1:

6Use a pair of wire strippers to cut through the insulation in the piece of wire that you intend to tap into.

 

Step 2:

7Then, move about 1/2 inch forward of that cut and make a second identical cut into the insulation.

 

Step 3:

8Use a razor blade to slice lengthwise from the first cut to the second cut.

 

Step 4:

9Remove the section of insulation from the wire.

 
 
 

Step 5:

10Insert a pick tool through the center of the copper wire and open a passage so that you can pass the second wire through.

 

Step 6:

Strip 3/4 inch of insulation from the end of the wire you are connecting to this one.

Step 7:

11Insert the bare copper wire Insert the bare copper wire through the passage you made in Step 5.

 
 
 

Step 8:

12Tightly wrap the wire around; be sure to get as much contact as you can between the two wires.

 

Step 9:

13Tightly insulate the connection with Super 33+.

 
 

Step 10:

14Use a small cable tie around the tape to keep the connection tight and a second small cable tie about 1 inch from the connection as a stress relief.

 
 

I’ve made thousands of both of these types of connections without a single problem. Like anything else, the key is knowing when to use them and how to do them properly. Note these connections are not suitable for 14-gauge and larger wire.

 

Crimp-Style Connections

This connection is simple to master, but before I show you the fundamentals of the connection itself, let’s talk first about the different types of crimp connectors available. Crimp connectors are available in sizes to accommodate up to the largest gauge of wiring, including the really big stuff.

Seam versus Seamless Connectors

Although they may look similar from the outside, they are absolutely not. Quite simply, seamless crimp connectors are cut from round stock so they are tube-like in nature. Cheaper seam-type connectors are cut from flat stock and rolled into a tube-like shape, so they have a seam that runs the length of the connection. This can be hard to see through the insulation of the connector, but you can typically look at the ends to tell which type of connector you have.

 

On the right, I removed some of the insulation from the connector. A quick look to determine what kind of connector you’re crimping ensures that you crimp it properly.

On the right, I removed some of the insulation from the connector. A quick look to determine what kind of connector you’re crimping ensures that you crimp it properly.

 

Yes, I think this is a lousy crimp tool. But, if this is all you have to use, it’s even more important to orient the connector in the tool correctly.

Yes, I think this is a lousy crimp tool. But, if this is all you have to use, it’s even more important to orient the connector in the tool correctly.

 

This is the right tool for a crimping job. Notice the seam is opposite the stake to prevent the stake from opening up the connector in the process of crimping, resulting in a questionable connection.

This is the right tool for a crimping job. Notice the seam is opposite the stake to prevent the stake from opening up the connector in the process of crimping, resulting in a questionable connection.

 

This is especially important to know before you crimp the connector.

I typically only use seamless connectors for this very reason, but if you’re crimping a seamed connector, be sure to crimp it in such a way that the seam isn’t opened up in the process. This is easily accomplished by verifying the seam is perpendicular to the tool and opposite the stake if you’re using a staking-type crimp tool.

Non-Insulated Connectors

Obviously, this type of connector has no insulation on it so it must be properly insulated after you’ve crimped it in place—typically with heat shrink tubing. These types of connectors are available in a wide variety—from butt connectors to ring terminals, seam or seamless. The proper crimp tool for this type of connector is a staking-type crimp tool.

 

Either of these tools is suitable to properly crimp non-insulated connectors. I don’t purchase non-insulated connectors, as one can simply remove the insulation from any insulated connector and have a non-insulated connector, should the need arise.

Either of these tools is suitable to properly crimp non-insulated connectors. I don’t purchase non-insulated connectors, as one can simply remove the insulation from any insulated connector and have a non-insulated connector, should the need arise.

 

Insulated Connectors

This is the most common of all mechanical connectors. Like their non-insulated cousin, these are widely available in all different types and sizes and can also be seam or seamless type. They can have vinyl or nylon insulation on them, and this insulation can be straight or flared at the ends. The trick here is to pick the connector that properly fits both the gauge and the insulation OD of the wire you are crimping it onto.

 

Insulated connectors are my connector of choice because it saves time when you don’t have to insulate the connector after the crimping has been done. I have many different types of these on hand to accommodate any crimping job that I may come across.

Insulated connectors are my connector of choice because it saves time when you don’t have to insulate the connector after the crimping has been done. I have many different types of these on hand to accommodate any crimping job that I may come across.

 

Notice how the plastic insulation of the 8 AWG wire itself fits nicely into the insulation around this crimp connector. Some connectors have flared ends (such as this one), while others do not. I find that flared end connectors offer a higher likelihood of a perfect fit. This is equally as important as the wire fitting into the ferrule itself.

Notice how the plastic insulation of the 8 AWG wire itself fits nicely into the insulation around this crimp connector. Some connectors have flared ends (such as this one), while others do not. I find that flared end connectors offer a higher likelihood of a perfect fit. This is equally as important as the wire fitting into the ferrule itself.

 

Heat Shrinkable Insulated Connectors

These are the nicest of all crimp connectors. Use them one time, and it’s hard to go back to anything else. But, they’re very expensive. The mechanics of using them are identical to typical insulated connectors, but the insulation is heat shrinkable to provide a weather-tight connection—perfect for under the hood, underneath the vehicle, or even marine use! Just crimp, and heat for a long-lasting waterproof connection.

 

These connectors provide an exceptional connection and insulation. Think of them as a combination of a crimp connector with a heat shrinkable insulation surrounding them. Some, such as the 3M ones pictured, even have glue in them to provide a waterproof connection!

These connectors provide an exceptional connection and insulation. Think of them as a combination of a crimp connector with a heat shrinkable insulation surrounding them. Some, such as the 3M ones pictured, even have glue in them to provide a waterproof connection!

 

Look closely at the glue at each end. These connectors are suited for even the most arduous environments. The glue helps to encapsulate the electrical connection and protect it from the elements.

Look closely at the glue at each end. These connectors are suited for even the most arduous environments. The glue helps to encapsulate the electrical connection and protect it from the elements.

 

Different Kinds of Crimp Connectors

One of the reasons that crimp connectors are so popular is the variety of connectors that are readily available. In addition, they’re relatively inexpensive. This makes it easy to have a good selection of them on hand—I buy them in bulk so that I never run out. In addition, I like to “stock” all the various sizes available so that I always have what I need for the task at hand. I prefer insulated connectors over noninsulated.

Butt Connectors: These are for making butt, or end-to-end, connections between two wires. This is one of the most common crimp connections, and these are readily available up to 8 AWG, with even larger sizes available on request.

Ring Terminals: The ring terminal is the second most common crimp connector. These are quite handy for terminating a wire to a connection point, such as a stud or bolt on the rear of a typical alternator. They’re also used extensively to terminate a wire to a ground point. These are readily available with all different diameter rings and as large as wire is available.

 

As you can see, I keep a bunch of crimp connectors on hand. This represents about half of the various sizes and kinds that you’d find in my garage.

As you can see, I keep a bunch of crimp connectors on hand. This represents about half of the various sizes and kinds that you’d find in my garage.

 

I generally have butt connectors from 18 AWG to about 6 AWG on hand. As you can see, I have both flared and non-flared types that allow me to select the right connector for the job. Although this is a very basic connection, each connector requires two crimps so it’s twice as important to install them correctly.

I generally have butt connectors from 18 AWG to about 6 AWG on hand. As you can see, I have both flared and non-flared types that allow me to select the right connector for the job. Although this is a very basic connection, each connector requires two crimps so it’s twice as important to install them correctly.

 

Fork Terminals (Spade Terminals): These are popular because they allow termination of a wire to a connection point and provide easy connection to said point. A ring terminal requires that you totally remove the nut from the bolt or stud you’re connecting to in order to establish the connection. A fork terminal allows you to simply loosen said bolt or stud and slide the terminal underneath. This is especially valuable when connecting to a barrier strip with multiple connections. These are readily available based on the diameter of the bolt that they need to fit around. I’ve been known to modify a ring into a fork on occasion!

Quick Disconnect Connectors: I use these a lot because I try my best to keep serviceability in mind when adding a circuit to any vehicle. I use these wherever I need a simple connection to be easily disconnected. A good example is when mounting a switch or light in a dash panel that is removable. When removing the panel, a quick disconnect connection on the switch or light allows the panel to be quickly removed. This pays off in spades if your dealer services your vehicle, and they need to remove said panel. Instead of cutting your wiring, they simply unplug it.

 A ring modified into a fork terminal. Simple and easy, this can be a real life saver if you don’t have a fork large enough for the job at hand.

A ring modified into a fork terminal. Simple and easy, this can be a real life saver if you don’t have a fork large enough for the job at hand.

 

The dash of my Mustang has two LEDs that monitor the operation of the installed water/methanol injection system. As they are mounted into the trim piece surrounding the cluster, quick disconnects allow a simple removal.

The dash of my Mustang has two LEDs that monitor the operation of the installed water/methanol injection system. As they are mounted into the trim piece surrounding the cluster, quick disconnects allow a simple removal.

 

Quick disconnects are readily available for wire and cables of all sizes. I prefer the fully insulated push-on connector style over the bullet style.

Quick disconnects are readily available for wire and cables of all sizes. I prefer the fully insulated push-on connector style over the bullet style.

 

Filling the body of a quick disconnect with lithium grease is always a great idea with using these connectors under the hood or under the vehicle. This is an old favorite of mine.

Filling the body of a quick disconnect with lithium grease is always a great idea with using these connectors under the hood or under the vehicle. This is an old favorite of mine.

 

There are two types: bullet connectors and push-on connectors. Obviously, they’re both available in male and female versions.

The push-on type makes a really good connection. I typically use this style of connector rather than a plug-type connector when dealing with fewer than four wires. With four or more wires, a male and female plug is really the correct way to do things. This connector is suitable for low-current use under the hood or vehicle as well. If you use them in this environment, I recommend that you fill them with white lithium grease before pushing them together. This helps keep the elements from affecting the electrical connection.

 

Fundamentals of Crimping: The Right Way to Do It!

Choosing the Right Tool for the Job

First and foremost, you need the right tool for the job. Most professionals, including myself, prefer a good stake type crimp tool for both insulated and non-insulated connectors. When using high quality crimp connectors, the stake will not pierce or tear the insulation.

 

What more do you need to know about this tool? Super deluxe, it ain’t.

What more do you need to know about this tool? Super deluxe, it ain’t.

 

Non-Staked Tools

This is any crimp tool that had a smooth radiused surface on both sides, such as the ones in the crimper/connector set available at your corner drug store.

These “squeeze-type” crimp tools just don’t give you enough leverage to make good-quality crimps. In addition, their contact surface is typically quite narrow. If you insist on using this kind of tool, invest in one of the nicer models from Snap-On or Klein, to name a couple.

Traditional Staked Tools

This is any crimp tool that had a stake (or point) on one side of the jaw and a half-round surface on the other. These are what the pros use because they offer excellent leverage and make great crimps. In addition, they are available in a number of different sizes—handheld up to about 8 AWG. Most stake tools have at least two openings. You need to choose the opening that best fits the connector you’re crimping. Properly chosen, this does not deform the connector, and the stake seats the connector fully on the wire without damaging the copper within it. I don’t know of a “one size fits all” tool.

 

MuscleCarB

 

For general, all-around small-gauge crimping, I’ve always liked the Klein crimping tools because they have color-coded handles—the red handle identifies the side of the tool with the stake. Klein crimpers (shown on page 21) can easily crimp up to 14–16 AWG insulated connectors and 10–12 AWG non-insulated connectors. The yellow-handled crimpers pictured are Ideal Model 30-425 and can crimp up to 8 AWG insulated or 4 AWG non-insulated connectors. (Snap-On offers a nearly identical set, P/N PWC30.)

Handheld Compound Action Tools

The red-handled crimpers (shown on page 21) are First Forever Model HD16L. These are a compound-type staking tool that provides increased leverage and can crimp up to 8 AWG insulated or 4 AWG non-insulated connectors. They are somewhat difficult to fit into tight places though. Another favorite is the compound crimping tools that have interchangeable dies like the one shown below from Paladin.

 

A compound-action crimping tool, such as this one, has jaws that accept a wide variety of dies. By swapping out the dies, this tool can perform many different functions, such as insulated connectors, pin/plug assembly, spark plug wire, and so much more. The tool itself is somewhat big and bulky and can prove difficult to get in a tight spot under the dash though.

A compound-action crimping tool, such as this one, has jaws that accept a wide variety of dies. By swapping out the dies, this tool can perform many different functions, such as insulated connectors, pin/plug assembly, spark plug wire, and so much more. The tool itself is somewhat big and bulky and can prove difficult to get in a tight spot under the dash though.

 

Included here are numerous dies that make all kinds of crimping tasks a snap.

Included here are numerous dies that make all kinds of crimping tasks a snap.

 

I originally bought this set for terminating RG-59 and RG-6 coaxial cable. As they’re universal, the dies available from MSD (and others) screw right in. As pictured, mine have the spark plug crimping die from MSD attached but many different dies are available. One such available is a non-staked die for crimping non-insulated connectors the right way as you can get enough leverage—like shown in the Tool Aid set.

 

Crimping Non-Insulated Connectors

Now that you know the basics, let’s tackle crimping a non-insulated ring terminal on the end of a piece of 16 AWG wire with the Klein crimp tool. Here’s the right way to do it:

Step 1:

Strip about 1/4 inch of the insulation off of the end of the wire.

Step 2:

32Twist the stripped end of the wire clockwise so that you can ensure that all strands of the wire can be inserted into the ferrule easily.

Step 3:

33Push the ring terminal over the end of the bare wire making sure that all of the wire is inside the ferrule—there should be at least 1/16 inch of wire sticking out the other end.

Step 4:

34Orient the crimp tool around the ring terminal so that the stake is opposite the seam.

 
 
 

Step 5:

35Squeeze the tool fully, thereby making the crimp.

 
 
 
 

36After crimping, grasp the connector and tug on it a little bit to be sure it’s seated on the wire properly. If you didn’t properly crimp it, it comes right off. This little check is good practice and is far better than having a connector come loose when you’re driving down the road!

 
 
 
 
 
 

Crimping Insulated Connectors

This is not much different from the above. Let’s tackle butt-connecting two 10-gauge wires together with a seamless butt connector using the Ideal crimp tool. Here’s the right way to do it:

Step 1:

Strip 1/4 inch of insulation from both wires.

Step 2:

37The two wires are properly prepared to be connected.

 
 
 
 

Step 3:

Twist the stripped ends of the wires clockwise.

Step 4:

38Insert the first wire into the crimp connector so that the copper fits fully into the ferrule and the insulation fits fully into the nylon (or vinyl).

 

Step 5:

39Orient the crimp tool around the butt connector on the half of the connector that the wire is within.

 

 
 
 

Step 6:

40Squeeze the tool fully, thereby making the crimp.

 
 
 
 
 
 
 
 
 

Step 7:

41Repeat this process for the other half of the connection.

When crimping seamless butts, reverse the orientation of the crimp tool for each half of the crimp. That way, one stake is on each side of the connector. This keeps the butt connection nice and straight. If you stake both on the same side, the butt typically ends up slightly curved.

If you’re crimping a seamed butt connector, be sure that the stake is always exactly opposite the seam. Both stakes are on the same side of the connector.

 

Crimping Heat Shrinkable Insulated Connectors

The method is the same as above with one extra step. Continue the example above as if you’d used this connector to begin with:

Step 8:

42After the connector has been properly crimped, heat it with a heat gun until the shrinkable insulation encapsulates the connection

If you want the workmanship under the hood of your car to exude quality and to stand the test of time, then this is the connector for you. These are simply the best money can buy.

Crimping Large Gauge Wire Connections

There are really only two ways to do this properly, and both require a special tool to get the job done right. You’re either going to need a hammer-type crimping tool (inexpensive) or the mack-daddy hexagonal compound crimping tool (very expensive). Keep in mind, you cannot use the hammer-type tool to make terminations in the vehicle. Although you can use the hexagonal compound crimping tool for such, both tools are more easily used to make your connections outside of the vehicle so plan accordingly.

 

Most hammer crimp tools look like this. This inexpensive tool is an economical way to properly terminate connectors on the end of 4 AWG and larger wiring.

Most hammer crimp tools look like this. This inexpensive tool is an economical way to properly terminate connectors on the end of 4 AWG and larger wiring.

 

Using the Hammer Crimp Tool

Use of this tool is easy and who doesn’t like to beat on stuff with a hammer occasionally? For this example, we crimp a ring terminal on the end of a piece of 4 AWG wire. Here’s the right way to do it:

Step 1:

44Strip the correct amount of insulation off of the wire with a razor blade; this  varies per the connector you’re crimping on to the wire, but you always want about 1/8 inch or so of wire sticking out the end of any big open ferrule connector (recall from last chapter—score and tear).

Step 2:

45Push the ring terminal over the end of the bare wire making sure that all of the wire is inside the ferrule. There should be at least 1/8 inch of wire sticking out the other end.

 

Step 3:

With the crimp tool on a hard flat surface, insert the wire/connector into the crimp tool so that the stake is opposite the seam.

Step 4:

46Use a hammer to drive the stake firmly into the ring terminal.

 
 
 
 
 

47It typically takes only one or two good whacks from a big hammer to get the job done properly. If you hammer too much, the stake can tear through the bottom of the connector, which will damage the integrity of the crimp.

 
 
 
 
 

Using the Hexagonal Compound Crimping Tool

This tool is really no more difficult to use than a standard handheld crimping tool. However, if you’re crimping big connectors, it takes a lot of force to get the job done.

For this example, crimp a ring terminal on the end of a piece of 1/0 AWG wire. Here’s the right way to do it:

Step 1:

Set the dies on the jaws for the gauge of connector you’re using—1/0 AWG in this case. (With this tool, the color-coded jaws correspond to a chart on the tool itself.)

Step 2:

48Strip the correct amount of insulation off of the wire with a razor blade—this varies per the connector you’re crimping on to the wire, but you always want about 1/8 inch or so of wire sticking out the end of any big open ferrule connector.

Step 3:

49Open the jaws of the tool fully, hold the tool by one handle, resting the other handle on the shop floor. With the other hand, insert the cable/ring terminal into the jaws of the tool, being sure to get the seam of the connector in the middle of one of the flat sides of the hex opening.

Step 4:

50As you begin compressing the tool and the crimp, you should be able to let go of the cable and use both hands to to compress the tool fully.

 
 
 

51

 
 
 
 
 
 
 

Step 5:

52When finished, the termination should look like this:

Depending on how long the ferrule of the connector is that you’ve used, you may elect to do a second identical crimp directly next to the first crimp. Obviously, you should take this into consideration before making the first crimp.

Using the Hexagonal Compound Crimping Tool

If the basics of crimping seem pretty simple to you (and they should), then what are the pitfalls folks fall into when making bad crimp connections? Here are a few:

  • Incorrect tool used—again, pliers and vises are not crimp tools!
  • Right tool used, but incorrect size opening chosen to make crimp, which results in the connector being deformed or the wiring damaged.
  • Poor-quality crimp connectors used.

 

OK, admit it, you have a few connections that look like these lurking in your vehicle presently. Look closely at the errors in these terminations. Look closely under the hood at the next gathering and you’ll see plenty of examples. From top to bottom, pliers were used to crimp a fork terminal, 10–12 AWG ring crimped to 16 AWG wire, connector was deformed by using an improper size crimp tool, a stake was driven into the seam of connector, connector is deformed by using improper size crimp tool and wiring exposed, stake was driven into the side of the connector.

OK, admit it, you have a few connections that look like these lurking in your vehicle presently. Look closely at the errors in these terminations. Look closely under the hood at the next gathering and you’ll see plenty of examples. From top to bottom, pliers were used to crimp a fork terminal, 10–12 AWG ring crimped to 16 AWG wire, connector was deformed by using an improper size crimp tool, a stake was driven into the seam of connector, connector is deformed by using improper size crimp tool and wiring exposed, stake was driven into the side of the connector.

 

  • Seamed connectors crimped with no attention paid to the orientation of the seam come apart quite easily.
  • Too much of the insulation of the wire stripped off, making it impossible to get the insulation of the wire to fit into the insulator of the crimp connector properly and leaving the connection uninsulated.
  • Wrong size connector used—if you don’t have the right size connector on hand, the auto parts store just down the road will!

 

Soldering Irons and Guns How-To

If you want to make the best connection in an automobile, soldering is the ticket. Contrary to popular belief, soldering is very easy and can be mastered in no time at all. First, let’s get the obvious out of the way and talk a little about safety.

Safety

CAUTION: A soldering iron or gun is a great tool indeed, but the heated end can cause severe burns if you come into contact with it. In addition, the only place in a vehicle that a soldering iron or gun belongs is in your hand. If you have to set it down, set it down on the floor out-side of the vehicle. Be careful where you point it, as it can burn holes in anything that it comes into contact with—plastics, seats, door panels, carpet, etc.

WARNING: Butane-powered soldering irons are so handy you’re tempted to use them anywhere. Don’t forget that this iron has an open flame so KEEP IT AWAY FROM THE BATTERY!

CAUTION: Most solders contain lead. Anyone who hasn’t lived under a rock for the last 30 years realizes the health hazards lead pose. Do your best to solder only in a well-ventilated place to avoid breathing solder fumes. You should also keep the solder out of your mouth—we’ve all used our teeth to pull a little more solder off the roll as we only had one free hand—bad idea! It is also a good idea to wash your hands thoroughly after handling solder or soldering.

Soldering Basics

Regardless of what kind of soldering tool you use, you’re going to need some solder. As I mentioned in the last chapter, you need a 60/40 lead-based rosin-core solder that is for electronics use—which diameter you use is personal preference. In addition, you need to be sure your tip is properly dressed. This is called “tinning”—see the owners manual of your tool for specifics on how to do this.

The most fundamental thing about soldering is how you get the solder into the connection and that is the magic. The correct way to do this is to heat the connection from below and “flow” the solder into the connection from above. Like anything else, this takes a little bit of practice and patience.

The basics apply to both soldering irons and soldering guns. Soldering irons are great for wiring up to about 14 AWG before they typically cannot heat the connection enough to allow solder to flow into it. Soldering guns take over from there and can typically be used for wiring up to about 8 AWG. Soldering guns typically have two temperature settings, controlled by the trigger, and can get hot quite quickly making them handy for automotive use.

 

Soldering Two Wires Together End to End

This is pretty basic, and there are two ways of doing it. The first method is really only suitable for 18-gauge or larger wiring. For this example, we use a soldering iron to solder two 18 AWG wires together end to end. Here’s the right way to do it:

Step 1:

54Strip 1/2 inch of insulation from both wires and twist their ends tightly.

 
 

Step 2:

55Tin the end of both wires by clamping them in your third hand jig and holding the iron under the wire and allowing solder to flow into the wire from above.

 
 
 
 

Step 3:

56Bend the ends of both tinned wires into a U-shape with needle nose pliers.

 
 
 
 

Step 4:

57Hook them together end to end and flatten the Us with the pliers.

Step 5:

58Use the iron to heat the connection from below, while feeding a small amount of solder in from above, thereby fusing the two wires together.

 
 
 
 

59

 
 
 
 
 
 

The second method is suitable for wiring up to about 12-gauge, although I have done this with 10-gauge wiring with a very high strand count and a high-powered soldering gun. For this example, we solder the same two 18 AWG wires together end to end. Here’s the right way to do it:

Step 1:

Strip about 3/4 inch of insulation from both wires.

Step 2:

60Hold them end-to-end with their bare copper ends crossing at a slight angle.

 
 

Step 3:

61Twist the two wires together by wrapping them around each other in a clockwise fashion.

 
 

Step 4:

62Hold the soldering iron under the connection and allow solder to flow into the connection from above.

 
 
 

63This is a bit tricky and takes some time to master, to get the wires twisted together properly. The benefit is that you do not have to tin the wires first. Either of these connections should provide a lifelong connection.

 
 
 
 
 
 
 

Soldering a Wire to a Pre-Existing Wire in the Vehicle

This is similar to the Westinghouse Split connection, but you solder the connection for better connectivity and reliability. For this example, connect a piece of 18 AWG wire to a pre-existing 18 AWG wire. Here’s the right way to do it:

Step 1:

Use a pair of wire strippers to cut through the insulation in the piece of wire that you intend to tap into.

Step 2:

Then, move about 1/2 inch forward of the cut you just made and make a second identical cut into the insulation.

Step 3:

Use a razor blade to slice lengthwise from the first cut to the second cut.

Step 4:

Remove the section of insulation from the wire.

Step 5:

Strip 3/4 inch of insulation from the end of the wire you are connecting to this one.

Step 6:

64Wrap this wire tightly around the pre-existing one.

 
 

Step 7:

65Heat the connection from below while flowing solder in from the top.

 
 

Step 8:

Tightly insulate the connection with Super 33+ tape.

 

Soldering Various Terminals

Soldering a terminal to the end of a piece of wire is no more difficult than soldering two wires together. Obviously, non-insulated connectors are the way to go here, and it’s not uncommon for me to have what I need in an insulated connector—no problem, I just remove the insulation with a pair of pliers. For this example, we terminate a piece of 8 AWG wire with a ring terminal with a soldering gun. Here’s the right way to do it:

Step 1:

66Strip 3/8 inch of insulation from the end of the wire.

 

Step 2:

Twist the stripped end of the wire clockwise.

Step 3:

67Push the ring terminal over the end of the bare wire making sure that all of the wire is inside the ferrule—there should be at least 1/16 inch of wire visible at either end.

Step 4:

68Clamp the wire in the third hand jig and heat the connector from below with the soldering gun while flowing solder into the open end of the ferrule.

 

 

Step 5:

69When you see solder in the wire on the other side of the ferrule, you know you have enough solder for the connection.

 

 

Insulating Connections

Thus far, all of the connections except two have not been insulated. The two types of post connection insulators are electrical tape and heat shrink tubing.

Electrical Tape

Use Super 33+ and ensure your hands are clean. When taping connections, I typically:

  • Tear off a piece that is the right length—tearing electrical tape takes practice—grab and snap! Done quickly, the tape does not stretch.
  • Wrap the tape very tightly over the connection.
  • Just as I come to the end, I ease up on the tension of the tape.

This provides a trouble-free insulator for many years and won’t unravel itself as it would if the tape were pulled tightly all the way to the end. When taping soldered connections, let the connection cool for a few seconds and wrap it while it’s still hot. The best thing about tape is that you can insulate any kind of connection after the connection has been made.

 

Nope, this isn’t a pre-made plastic insulator. This is what a properly insulated connector looks like after you’re done taping it. Just remember to ease up on the tension slightly as your finishing your tape job, so you keep the tape from pulling loose over time.

Nope, this isn’t a pre-made plastic insulator. This is what a properly insulated connector looks like after you’re done taping it. Just remember to ease up on the tension slightly as your finishing your tape job, so you keep the tape from pulling loose over time.

 

Heat Shrink Tubing

Unlike electrical tape, heat shrink tubing isn’t “one size fits all.” You also can’t apply it to any connection after the connection has been made, as you can with tape—nope, this takes a bit of thinking ahead. I typically buy heat shrink tubing in 3-foot lengths and I have it in all different diameters and colors, including white, which I use to label my wiring.

When using heat shrink tubing, slip it down the wire before making the connection. Also, keep it far enough away from the heat so that it doesn’t shrink on the end nearest the connection as you’re making it. It’s always best to use slightly more than you need to insulate a connection, so on the off chance that does happen, you can cut that off with a razor blade and you’re still in business. Slide the tubing over the completed connection and heat it with a heat gun until it shrinks tightly around the connection.

Heat shrink tubing is certainly handy. It comes in sizes from 1/8 inch to more than 3 inches in diameter. I use it for all kinds of stuff, so I keep plenty of it on hand in all different colors.

Heat shrink tubing is certainly handy. It comes in sizes from 1/8 inch to more than 3 inches in diameter. I use it for all kinds of stuff, so I keep plenty of it on hand in all different colors.

 

Heat shrink tubing gives your work a very professional look. Just remember to slide it down the wire before making your termination.

Heat shrink tubing gives your work a very professional look. Just remember to slide it down the wire before making your termination.

 

Heat shrink tubing yields the most professional looking results of any insulator. If you want folks to look at your work and think wow, then heat shrink tubing is the only way to go. Heat shrink tubing has many other uses, a few of which you’ll learn later in the book.

 

MuscleCarB

 

Temporary Mechanical Connectors

This type of connector is all too common in automotive use. These refer to any connector that is designed to be installed over an insulated wire—like T-Taps or Scotchlok connectors. These are only suitable for low-current applications because they have quite a small contact area. In addition, as they are not weather tight, you’d never see me use these under the hood or under a vehicle to connect, say, a trailer harness. I like to think of these as temporary connectors because they do not offer the reliability of a properly crimped or soldered connection.

 

Temporary mechanical connectors are only suitable for short-term connections. If you do have to use a T-Tap for any reason, this is how your finished installation should look. The cable tie acts as a strain relief.

Temporary mechanical connectors are only suitable for short-term connections. If you do have to use a T-Tap for any reason, this is how your finished installation should look. The cable tie acts as a strain relief.

Incidentally, I’ve repaired more “connections” made with these than any other—I can’t tell you how many times I’ve solved major problems when fixing someone else’s work by removing these entirely and using a different method of connection.

Scotchlok Connectors

These are the easiest connectors to install. Be sure that the connector you’re using is properly sized for the wire you’re putting in it. If you’re using this connector to connect two different-size wires together, you’d be best advised to pick another connection method. These are color coded via the same scheme as insulated crimp connectors.

T-Tap Connectors

These remain a favorite among those who perform auto security and remote starter installations because they pride themselves in speed. Their installation is slightly more complex—the T-Tap itself is closed around the wire that you’re tapping into.

Then, crimp a male push-on connector onto the wire that you’re connecting to the wire above. Slide the spade into the body of the T-Tap for a quick connection. Admittedly, this connector can be a life saver if you’re trying to tap into a wire that is in a very-difficult-to-reach spot. Even still, I’ve used fewer than 10 of them in my time working on autos. These are also color coded via the same scheme as insulated crimp connectors.

 

When using a T-Tap, it’s important to use the one that properly fits the wire you’re connecting to. Using a T-Tap or Scotchlok connector that is too small cuts through the copper in the wire that you’re tapping into, and thereby the connector damages the integrity of wire and the circuit it’s part of.

When using a T-Tap, it’s important to use the one that properly fits the wire you’re connecting to. Using a T-Tap or Scotchlok connector that is too small cuts through the copper in the wire that you’re tapping into, and thereby the connector damages the integrity of wire and the circuit it’s part of.

 

This is a T-tap connection at its most basic. Notice the connector and male push-on terminal are both sized properly for the 18 AWG wiring, in this example.

This is a T-tap connection at its most basic. Notice the connector and male push-on terminal are both sized properly for the 18 AWG wiring, in this example.

 

Between Scotchlok and T-Tap connectors, I’ve seen a range of problems. Typically, the wrong-size connector is used. Too small of a connector can cut into the wiring your connecting it to, thereby compromising its integrity. Too big of a connector doesn’t get a good grasp on the wire.

Wire Nuts and Crimp Caps

I do not recommend wire nuts whatsoever for automotive use. There are many better connections. If you like the simplicity of a wire nut, use a crimp cap instead and rest assured it will not come loose! Simply twist the wires together to be connected, slide the cap over the connection and crimp. I don’t use these too often because I don’t like the look of the finished product.

 

Wire nuts are great for home wiring jobs with solid wire, and that’s about it. If you need to connect two wires that are side by side at their ends, use a crimp cap instead.

Wire nuts are great for home wiring jobs with solid wire, and that’s about it. If you need to connect two wires that are side by side at their ends, use a crimp cap instead.

 

Fuse Taps

Stay away from these! These connectors are designed to slide under the fuse in the fuse box of a vehicle and provide a push-on terminal tap for power.

 

Folks, fuse taps just aren’t the way to do things properly. Read on to learn how easy it is to find a source of power, making this type of connection totally unnecessary.

Folks, fuse taps just aren’t the way to do things properly. Read on to learn how easy it is to find a source of power, making this type of connection totally unnecessary.

 

I have numerous problems with this; here are my top three objections:

  • Number 1: The manufacturer has a pretty good idea of the current capacity of the fuse panel in your car. Shoving wiring under a fuse in the panel is not a safe way to power up your new accessory, as you could exceed the safe current capability of the circuit.
  • Number 2: Most people install these incorrectly! How so?Simple. A fuse tap should always be installed under the load side of the fuse and not the power side. Get it backward, and the length of wire from the fuse tap to your accessory will burn if it becomes pinched or shorted. I just witnessed this happen in a car.
  • Number 3: If the fuse tap is removed for any reason, the fuse can no longer make good contact with the fuse box because the contact points have been spread out to allow the fuse tap to fit. The fix is to use a small flat blade screwdriver to bend the contacts back to where they were to begin with, but I can’t tell you how many times I’ve had to charge someone two hours of labor to track down and repair this!

It’s just too easy to find a source of power under the dash of a car with your DMM that doesn’t involve tapping under a fuse. Just say no to these and be safe. You’ll thank me in the long run.

 

Distribution-Type Connectors

These are commonly found on aftermarket electronics, such as ignition boxes and audio amplifiers, but you can also purchase them for wiring projects. I use them a lot because they give me a great place to terminate connections between different components. They’re available in two types—barrier strips and cinch-type. Both are available at most auto parts stores as well as Radio Shack in different sizes and lengths.

 

These barrier strips are found in numerous places in automotive use. Connecting to them requires the correctly dimensioned fork terminals in order to fit the barrier strip.

These barrier strips are found in numerous places in automotive use. Connecting to them requires the correctly dimensioned fork terminals in order to fit the barrier strip.

 

Connectors and Plugs

Work on vehicles long enough, and you come across all kinds of connectors and plugs. The number-one reason that manufacturers use them is to speed up assembly and disassembly when it comes to servicing the vehicle after it’s been built. Imagine how difficult it would be to remove a console or dash from a vehicle without these. The nice thing is that you can purchase and install them as well. This gives your wiring project the same kind of serviceability the rest of the vehicle has.

Molex Plugs

The word Molex is to these types of connectors that Coca-Cola is to soft drinks. There are a bunch of different manufacturers of these kinds of plugs, and they’re all similar in use. I bought a four-pin male and female set designed for 18 AWG wire at Radio Shack for this example. I’ve seen these available for up to 12 AWG wire at various electronics parts houses.

 

Radio shack is a great source for connectors of all types, including these. I picked up some Molex brand plugs at the local Fry’s Electronics. The plugs come as kits with pins and the male/female connector bodies for many different configurations and wire sizes. Best of all, they were less than $5 a pack.

Radio shack is a great source for connectors of all types, including these. I picked up some Molex brand plugs at the local Fry’s Electronics. The plugs come as kits with pins and the male/female connector bodies for many different configurations and wire sizes. Best of all, they were less than $5 a pack.

 

Tools Required

Really, the only tool you need is the crimping tool itself. Pictured is the one that works with this connector, but depending on the connector you purchase, it may call for a special crimp tool.

 

This is a run-of-the-mill pin-crimping tool. These are readily available at your local Radio Shack or your local electronics supply house.

This is a run-of-the-mill pin-crimping tool. These are readily available at your local Radio Shack or your local electronics supply house.

 

If you have a set of compound crimpers with interchangeable dies, you can usually buy just the die for that tool versus buying a whole new crimp tool. It’s also nice to have a pin extractor for the unlikely event that you have to remove a pin from a plug. They’re inexpensive and typically sold at the same places you buy crimpers.

If you don’t have the tool, you can use a pair of needle-nose pliers to do the crimping and a soldering iron to ensure the connection is solid. It’s painfully slow but works equally well.

Assembly

The assembly of all types of connectors is similar—Molex, GM Weatherpack, or Deutsch, so I’m just going to cover one of them. First, let’s take a look at the pin itself. Notice that there are two crimping points—on the right is where the pin is crimped to the copper wire and on the left is where the pin is crimped to the insulation of the wire as a strain relief.

 

Look closely. The strain relief on the far left is crimped around the insulation of the wire. The wire is connected to the pin electrically via the part of the pin just to the right. The crimp tool bends both in a U-shape to hold the pin on the wire firmly.

Look closely. The strain relief on the far left is crimped around the insulation of the wire. The wire is connected to the pin electrically via the part of the pin just to the right. The crimp tool bends both in a U-shape to hold the pin on the wire firmly.

 

These are the pins available in the plug kits at Radio Shack. You have to cut them apart before you can use them. It’s also necessary to leave some of the metal in place when you make your cut and keep the pin from pushing through the back of the connector.

These are the pins available in the plug kits at Radio Shack. You have to cut them apart before you can use them. It’s also necessary to leave some of the metal in place when you make your cut and keep the pin from pushing through the back of the connector.

 

Note also that there are male and female pins as well as male and female plugs. It’s important to keep these oriented correctly so that you can assemble them, so pay attention!

 

Assembling Connectors

Assembly is easy. Here’s the right way to do it:

Step 1:

83Strip 1/8 inch of insulation off of the end of the wire and put the wire in the pin as shown.

 

Step 2:

84Holding the two together, insert them into the crimp tool and crimp the pin to the insulation of the wire first. This provides the strain relief for the electrical connection itself.

 

Step 3:

97Remove the pin from the tool and re-orient it in the correct spot to crimp the pin to the wire.

 
 

Step 4:

85Correctly crimped, it looks like this.

 

Step 5:

86Insert the pin into the body of the plug in the correct orientation. Make sure that it “snaps” or locks into place and confirm this by tugging on it gently to verify that it doesn’t come out.

 

Step 6:

Repeat for the rest of the pins—male and female.

A completed assembly typically looks like this:

The fully assembled plug. Notice that this plug has a female body with male pins.

The fully assembled plug. Notice that this plug has a female body with male pins.

This is a very time consuming process, and it takes a bit of practice to get good at. I’ve actually gone to the trouble of soldering the pin to the copper after I’ve crimped them to ensure they don’t ever come loose, but I’m sure that doesn’t surprise you by now. Finally, some of the plugs allow you to orient the male/female pins into the male/female plugs any way you like. This is quite handy if you have multiple connectors with the same pin count and you don’t want them to be accidentally plugged into one another.

 

Basics for AWG Wire 8 and Larger

When you have to work with big cables, and you often do when working on a vehicles charging system, there are some additional things you need to know.

Tools Required

  • Battery cable cutters designed to cut large soft copper cable (OK, a hacksaw works nicely in a pinch).
  • Large AWG crimp tool—be it the hammer type or hex crimp type, or cheaper yet…
  • Propane or MAPP Gas Torch—I bet you already have one of these in your tool box anyhow!

 

When working with large-gauge wiring and connectors, you can get by with only a torch and pair of cable cutters. The Klein cable cutters here are their model number 63050 and available at your local home improvement store.

When working with large-gauge wiring and connectors, you can get by with only a torch and pair of cable cutters. The Klein cable cutters here are their model number 63050 and available at your local home improvement store.

 

WARNING: Wielding torches is dangerous enough. Because they have an open flame, avoid using them near a battery. To be safe, I recommend using them at your work-bench only.

 

Soldering Large AWG Connectors

Let’s say that we need to solder connect the same 1/0 AWG ring terminal on the end of the same piece of wire that we did with the big-dollar hex crimp tool, only we didn’t have that tool. No problem, equipped with an inexpensive torch, we can do the job—and better!

Here’s the right way to do it:

Step 1:

Fill a small cup with cold water and set it nearby.

Step 2:

Strip the correct amount of insulation off of the wire with a razor blade as before.

Step 3:

89Clamp the cable softly in a bench vise in a vertical fashion and slide the ring terminal over the wire so that 1/8 inch or so of wire is visible at each end of the ferrule.

 
 
 
 
 
 
 
 

Step 4:

90Heat the ring terminal and wire with the blue end of the flame in your torch, being careful not to burn the insulation of the wire—a little won’t hurt anything, but this isn’t good to breathe, either.

 
 
 
 
 

Step 5:

91As the wire and ring terminal get to temperature, you can now flow solder into the connection from the top. (Tip: To keep from burning up the solder with the torch, move the flame of the torch away from the connector.

 
 
 

Step 6:

Feed solder from the bottom up into the connector to complete the connection.

Step 7:

92When your connection looks like this, remove the heat from the connection and turn off the torch.

 
 
 
 

Step 8:

93Carefully remove the wire from the vise and dip the ring into the cup of water, being careful that it doesn’t fall off, to cool and complete the connection.

This takes some practice to get it down to a science. Don’t worry about burning up the insulation on the wire with the torch, as you’re going to do it anyway the first few times you attempt this. Plus, it’s easily covered with heat shrink tubing or the plastic insulator that came with the ring terminal, which you’re going to use to insulate the connection anyhow.

Large AWG Distribution-Type Connectors

Working with large-gauge wire can be frustrating when connecting it together. Fortunately, there are more such products available today than ever before. Distribution blocks, battery clamps, and fused distribution blocks are just a few examples of what’s available today. A great source of these is your local car stereo shop.

 

Large-gauge wire distribution products are now readily available thanks to the car stereo industry. The block on the left is an ANL fused distribution block that accepts up to 1/0 AWG wire for both its input and outputs. The block on the right is a MAXI fused distribution block. Its inputs accept up to 1/0 AWG wire, and up to 4 AWG wire for its outputs. These are also available without the fuses.

Large-gauge wire distribution products are now readily available thanks to the car stereo industry. The block on the left is an ANL fused distribution block that accepts up to 1/0 AWG wire for both its input and outputs. The block on the right is a MAXI fused distribution block. Its inputs accept up to 1/0 AWG wire, and up to 4 AWG wire for its outputs. These are also available without the fuses.

 

A termination like this is not difficult to perform, and it has the lowest resistance of any large-gauge termination. Rest assured this connection will not come apart. Be warned, it takes a bit of practice to master the assembly technique.

A termination like this is not difficult to perform, and it has the lowest resistance of any large-gauge termination. Rest assured this connection will not come apart. Be warned, it takes a bit of practice to master the assembly technique.

 

The Anderson Connector is a functional and practical high-current, quick-disconnect connector, and it’s one of my all-time favorites. A pair of very high-current “pins” terminates the end of the wiring and then snaps into the plugs. The ferrules of these pins are typically 2 inches long so they allow dual crimps to ensure they won’t come off.

The Anderson Connector is a functional and practical high-current, quick-disconnect connector, and it’s one of my all-time favorites. A pair of very high-current “pins” terminates the end of the wiring and then snaps into the plugs. The ferrules of these pins are typically 2 inches long so they allow dual crimps to ensure they won’t come off.

 

Large AWG Quick Disconnects

Think of these as giant-sized Molex plugs able to handle incredibly high currents. I’ve always known these as “Anderson” connectors and a Google search confirmed that.

These are available up to 4/0 AWG and are handy when you need a reliable high current disconnect. I’ve used these connectors for years and have not a single problem to report. They are used in very high current applications—like the biggest of winches and for connecting the battery packs on fork lifts to their respective chargers.

These are typically crimped on the ends of the cable, and they are same-sex connectors. In addition, the (+) and the (-) can only go one way, which eliminates the possibility of connecting them incorrectly.

These provide a fast connection between a battery charger and battery in a race car—just pop the trunk and plug the connectors together. No worries about getting the cables reversed—ever!

 

Written by Tony Candela and Posted with Permission of CarTechBooks

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