GL1200 Electrical System - Crimp Systems 101

[Rednaxs60]

Crimp Systems 101

This article is quite long and involved. I thought that a subject on crimping of wire crimp terminals would be straight forward, and a relatively short and easy expose. I have since found that this is not the case.

This is the follow-on article to GL1200 Electrical System – Connecting to the System.

The other threads that have preceded this one are:

GL1200 Electrical System – Connecting to the System: viewtopic.php?f=12&t=12727
Power Junction: viewtopic.php?f=12&t=12677
GL1200 Electrical System: viewtopic.php?f=12&t=12703
1985 GL1200 Rectifier Testing: viewtopic.php?f=24&t=12722

I have increased my understanding of the subject and in doing so, intend to apply some of what I have learned to the electrical wiring on my '85 LTD.

I submit the information regarding this subject as my summation/consolidation of the research I have done and trust that you will find it informative and helpful.

Have a good read. Cheers

Anatomy of an Insulated Crimp Terminal

The parts of a crimp terminal are:

Parts of an Insulated Crimp Terminal

You will notice there is one wire crimp area that has a crimp area and a strain relief area. The crimp terminal with a strain relief area is called a three piece/part insulated terminal. To use these 3 part crimp terminals, a double crimp tool is required. These 3 part crimp terminals are widely used in OEM wire harness connectors. A 3 part crimp terminal is considered to be of a higher quality and much better used than a single part crimp terminal.

The strain relief crimp removes the strain from the crimped wire and uses the wire insulation to absorb any tugs, pulls, bends, etc. There is no strain relief barrel on a heat shrink terminal. The adhesive glue, combined with the insulation, provides the strain relief on a heat shrinkable terminal.

Solderless or Stakon connectors are crimp terminals. There are two varieties of these. There are the connectors that have a plastic protective coating around the wire end or over the entire connector. These crimp terminals are also available with heat shrink plastic coatings.

Solderless/Stakon Crimp Terminals

The crimp terminals in the top row are high grade crimp terminals with built in adhesive lined heat shrink and are the best possible solution, for most applications.

The second row of crimp connectors are called insulated crimp terminals but are not heat shrinkable. The ring crimp terminals are a what are considered a three-piece terminal and the butt splices are a solid tube with no seam. These crimp terminals are much better than the crimp terminals in the bottom row, but are not sealed connections.

The third row represent inexpensive and lower quality crimp terminals that tend to vary tremendously in ID and OD., and as such the quality of the crimp cannot be guaranteed.

A good tip when buying connectors is this; if you can’t see through the insulation, it’s most likely vinyl, and should really be avoided. The vinyl insulation on this type of connector can and will crack and the raw metal thickness, where the wire meets the connector to be crimped, is very, very weak in comparison to top quality terminals from manufacturers such as AMP/Tyco, Molex, FTZ, Burndy, Thomas & Betts (T&B), 3M, Ancor to name a few.

There are solderless/Stakon crimp terminals that do not have any protective plastic coating, but once the crimp is made, shrink tubing can be used to protect the connector.

Unprotected Solderless/Stakon Wire Crimp Terminal

This unprotected crimp terminal shows a brazed seam. This emulates a crimp terminal barrel that is manufactured with a seamless barrel and provides a crimp that can pass very stringent requirements even when using a mid grade crimp tool.

Crimp Terminal with Non-Brazed Seam

The picture above illustrates a wire crimp with a non-brazed seam. The crimp is quite good, but because the seam of the crimp terminal is not brazed, the seam is starting to open reducing the effectiveness of the crimp.

Crimp terminals with solid or brazed seams are recommended over the crimp terminals that do not have these qualities.

A good quality crimp terminal will be made of tin plated copper, not aluminum, and with this comes the downside, a good quality crimp terminal will be more expensive. You should be able to go on-line and find good quality crimp terminals at a reasonable price without going to a marine chandlery.

Tin Plated Copper Crimp Terminal

This picture is an illustration of a quality tin plated copper crimp terminal with the tin plating scraped off the terminal end. A quality crimp terminal may also have the wire size gauge on it as well. The CNS on the crimp terminal indicates crimp and seal. Another feature of this crimp terminal with heat shrink insulation is that the crimp terminal is sealed at the front of the crimp terminal barrel so that when the crimp is made and the heat shrink insulation is closed around the wire insulation, a relatively good air tight crimp is made reducing the possibility of corrosion in the wire.

Another advantage of a crimp terminal with heat shrink insulation is that a 3 part crimp terminal, one with a strain relief, is not required as the heat shrink performs this function.
The quality of butt crimp terminals varies as well as depicted in the following pictures:

Butt Crimp Terminals

Butt Crimp Terminal Barrels – Insulation Removed
You will notice the difference in the two butt terminals in the length of the terminal inside the insulation.

The two terminals were measured as well. The top, least expensive butt crimp terminal had an OD of 5.36 mm – ID of 3.69 mm. The bottom more expensive butt crimp terminal had an OD of 5.52 mm – ID of 3.38 mm, and as such is more robust and of course, more expensive.

It was also noted that the jaws of a good quality crimp tool are wider than the total crimping area of the less expensive butt crimp terminal.

There are a multitude of other connectors not recommended for wire connections on our bikes. A couple of these are the Scothlok connector:

Scothlok Connector

These connectors are used quite often in the automotive industry for a variety of uses but quite often for trailer wiring connectors. These can be used on our bikes, but not recommended as a best practice.

Another connector that has been documented as being used are the house hold wiring connectors used to join solid core wire.

Solid Wire Connectors

These have also been documented as being used for wiring changes on bikes. Again, this is not recommended as a best practice and should not be considered.

A good set of wire cutters and wire strippers is also recommended.

Have run out of picture space. Onto Post #2.

 

[Rednaxs60]

Crimp Systems 101 - Part 2

Crimping is a form of wire termination used the world over and is the number one method used. It is used in multiple industries. Done correctly utilizing the proper tools crimping is extremely reliable.

There are a few key points with crimping that I found on the web hat are applicable to the motorcycle environment:

To create a proper cold-formed termination between the terminal and wire
To use tools and terminals that result in consistent & easily repeatable terminations
To use wire and terminals that are appropriate for the environment
To produce terminations that don’t result in high resistance
To choose terminals that are made from tin plated copper not aluminum
To choose tools that allow for a repeatable crimp before releasing
To use proper technique which will result in a reliable time tested and proven terminations

In this regard, what tools should you have to do the various connections. For soldering there are a variety of soldering irons available, with the only limiting factor being cost. For solderless connections, a good crimp tool and one that has multiple crimp dies is highly recommended.

Wire Crimp Tool with Multiple Crimp Dies

Assortment of Wire Crimp Tools

This picture illustrates various types of wire crimp tools that have been used at one time or another.

The vice grip on the far left is not a crimping tool, but is probably used more often than one would expect. Ordinary pliers have also been used. I can appreciate the use of these tools for emergency repairs, but a permanent repair should be done as soon as possible afterwards with the proper tool(s).

The next crimp tool, the one with the yellow handles, is an inexpensive hardware store quality crimp tool. This particular style of crimp tool is probably the most used of all the crimp tools; however, longevity and quality of the “crimp” is not the best, and you will probably be replacing this type sooner than later.

The middle tool is a middle grade strip & crimp tool. It is suited for crimping non-insulated terminals and stripping wire, but consistency may be suspect.

The fourth tool is a decent DIY grade crimp tool intended for heat shrink crimp terminals. This one is made by FTZ Industries a US manufacturer of crimp terminals and crimp tools. FTZ actually invented the heat shrink crimp terminal. This tool is designed specifically for crimping marine or aviation grade heat shrink terminals. The jaws of this crimp tool are fairly well machined, and wide enough in cross section, to produce a decent quality crimp. This crimp tool is also of the controlled cycle or ratcheting type, and will not release until a proper crimp has been made.

The final crimp tool shown is another ratcheting type, but this one, set up with the jaws shown, is designed for insulated crimp terminals. It makes a “double crimp” for insulated terminals.

The crimp tool in the first picture is a ratcheting type crimp tool and the various crimp dies are shown. These can be found on sale for a very reasonable price, have the various crimp dies so that one crimp tool does multiple types of crimping.

Industrial Grade Dimple Crimp Tool

This industrial crimp tool depicted above, also called a dimple crimp tool, does a good job crimping non-insulated crimp terminals from 8 to 20 GA wire. It is limited in what connectors can be crimped.

There are a host of off-shore wire crimp tools that look like and could emulate a good quality crimp tool made in Europe or North America. These crimp tools need to be carefully assessed to ensure the crimp dies and crimp quality will be the same.

Off-Shore Crimp Tools

One issue with these off-shore crimp tools is with the double crimp dies. Ensure the double crimp die set is directional. Some of these off-shore crimp tools have double crimp die sets that are non‑directional meaning that the strain relief side and the wire crimp side are identical. The wire crimp and strain relief sides are not identical in size.

There may be other concerns regarding the die sets; however, the information regarding the die sets is not always available when you order one of these off-shore crimp tools.

Dimple Crimp Tool

In this photo, a heat shrink crimp terminal has been placed into the jaws of a dimple or staking crimp tool. It illustrates why a dimple crimp tool should not be used on an insulated crimp terminal. Once you squeeze the grip the dimple can puncture the crimp terminal insulation, rendering the insulation protection ineffective. The seam of the crimp terminal in this picture is also on the same side as the dimple. This is the wrong way to crimp a crimp terminal with a seam using a dimple crimp tool. The seam should be on the opposite side to the dimple.

Crimp Terminal Barrel Seam

If, or when you do use a dimple/staking crimp tool the dimple is always made opposite the seam. This is applicable to crimp terminals that have brazed seams as the crimp tool dimple can split the brazed seam. When you use better quality crimp terminals, you will be able to see the seam through the protective insulation. If you use the inexpensive crimp terminals with a vinyl coating, you should be able to look into the crimp terminal barrel and determine the orientation of the seam.

Why use a good quality and correct crimping tool for the job at hand? The following picture is an example of how good quality terminals can be ruined by using the incorrect crimp tool.

Heat Shrink Insulation Destroyed

This is an excellent example that illustrates why it is important to use the correct tool for the job.
These expensive heat shrink crimp terminals were destroyed because a staking/dimple crimp tool was used. These crimp terminals require a tool specifically designed for heat shrink terminals.

For insulated crimp terminals, and I have and do use the inexpensive crimp terminals, the proper crimp tool has been, in my opinion, adequately covered. Here are pictures of the difference between a good quality insulated crimp terminal tool and a less expensive crimp tool.

Quality Versus Low Quality crimp Tools

You will notice the difference in the crimp tool thickness. The bottom crimp tool will give a better crimp and a wider crimp band.

Crimp Tool Jaw Surfaces

In this picture you will notice the smooth crimp surfaces that will not ruin/destroy the crimp terminal insulation.

There is also a difference between lesser quality crimp tools and mid to high quality crimp tools in that the lesser quality crimp tools tend to squash the crimp terminal into an oval shape instead of compressing the crimp terminal as depicted in this picture.

Crimp Shape
The crimp on the left is a controlled compression crimp from a mid to high quality ratcheting crimp tool. The crimp on the right is from a lesser quality dimple crimp tool. This crimp is not as consistently oval as the one on the left, and as such, of lesser quality.

When a crimp terminal is squished with no control over the squish area whereas there is a compression type crimp in a controlled space with a mid to high quality crimp tool. The crimp die is manufactured to properly fit the crimp terminal such that when the force of the crimp tool is applied to the crimp terminal, the jaws compress the crimp terminal into a designed oval shape so that there is a more 360 degree compression of the terminal resulting in a well made, cold fused wire crimp.

Onto Crimp Systems - Part 3

Cheers

 

[Rednaxs60]

Crimp Systems 101 - Part 3

Crimping 101

As with everything we do, there are sources of best practice for the application in question. I will try to present a Reader's Digest version of this information.

Use a good pair of wire cutters. Making a clean cut will enable the wire to strip well and slide into the crimp terminal easily.

Well Cut Wire Ready For Strip and Crimp

The next step is to strip the wire trying not to nick or remove any wire strands. A good wire stripper may have AWG and SAE markings on the stripping dies. Use the appropriate die for the wire being used. A good wire stripper will do clean and repeatable strips.

Wire Strippers

Wire Stripped
After the wire is stripped, check it for length in the crimp terminal. The wire insulation should butt up against the crimp terminal.

Wire – Crimp Terminal Test

To properly view the wire insulation up against the crimp terminal, the better quality crimp terminals with see through insulation are recommended.

Good Crimp Connection

An advantage of the ratcheting crimp tool over a manual crimp tool is that a good quality ratcheting crimp tool will release once the crimp is done correctly. The above picture illustrates a well done completed crimp.

I mentioned earlier that there are 2 and 3 part crimp connectors, and that 3 part connectors are recommended because of the strain relief aspect. This picture illustrates a well done 3 part terminal crimp.

3 Part Crimp Terminal

When doing a 3 part crimp terminal crimp, ensure the crimp tool die is positioned in the correct orientation because one side of the die is deeper than the other.

3 Part Crimp Tool Crimp Die

This crimp tool allows for both the bare wire crimp and the strain relief sleeve to be crimped in one motion, at the same time, and will not release until the full crimp has been made. You will also notice that the crimp die is directional as the wire crimp side of the die is shallower than the strain relief side.

To carry on, the wire strip depth needs to be correct. The wire depth should just protrude past the end of the crimp terminal barrel.

Wire Depth

Wire Depth Side View

Onto Crimp Systems Part 4

Cheers

 

[Rednaxs60]

Crimp Systems - Part 4

Here are some additional pictures to illustrate some of the crimp terminal crimps that have been seen.

Wire Too Long for Crimp

This picture illustrates a crimp where the wire is too long for the crimp terminal. This should be removed and a new crimp made with the wire being of the appropriate length.

Wire Strands Outside of Crimp Terminal Barrel

All wire strands need to be inside the crimp terminal barrel. Crimp should be redone to ensure that there are no loose strands.

Wire Insulation Stripped Back Too Far

This picture illustrates that the wire insulation has been stripped back too far for the respective crimp. Recommended to remove this crimp and redo.

To ensure a correct and repeatable crimp, the quality of the tool and the jaw movement helps immensely. The easiest crimp tool jaw movement to use to get consistent well done crimps is a parallel jaw movement.

Parallel Jaw Crimp Tool

This is a parallel style crimp tool, sometimes called a guillotine-style tool. The dies come together vertically so all you need to do is insert the terminal with the seam aligned vertically, and then squeeze. The down side is that parallel movement crimp tools are a lot more expensive.

The next easiest crimp tool to use is one that has a ratcheting jaw action as has been described.

There is a crimp tool that has scissor like crimp jaws and as the name suggests, the jaws articulate like a pair of scissors. These can prove consistent and well done crimps; however, more practice and experience with this type of crimp tool is required.

Scissor Jaw Crimp Tool

There are good and not so good crimps. The pictures below illustrate the differences. The left crimp terminal is far superior to the one o the right.

Crimp Differences With Insulation

Crimp Differences Insulation Removed

The quality of the crimp is a key element in the longevity of the crimp, the operation of the device the crimp affects, and the possibility of corrosion.

Tale of 2 Crimps

The picture above illustrates the difference between a well made crimp on the left with a mid to high grade ratcheting crimp tool, and the one on the right made with a lesser grade dimple crimp tool. The crimp on the left has cold welded the wire into an almost solid mass whereas with the crimp on the right, you can see the wire strands in the crimp terminal. The difference in these two crimps affects the corrosion resistance of the crimp. Because of the almost solid mass of the wire in the crimp terminal on the left, there is less chance for corrosion then with the crimp on the right.

There is also a lot of discussion, comments, recommendations to be found regarding whether to solder a crimp connection. Soldering is generally used to provide a solid mass connection that results in good conductivity, longevity and is corrosion resistant. The picture above illustrates that with a mid to high grade crimp tool of the appropriate type for the requirement, an almost solid wire mass can be achieved giving the same results as a soldered wire joint.

Using solder with a well made crimp, does not necessarily result in a better crimp joint. Crimp systems are designed to compact the wire strands together so that no gaps (interstitial spaces) are left between the strands. Wires compacted in a well done crimp are also referred to as being cold worked, or cold formed.

With the wires cold worked or cold formed into an almost solid mass, the possibility of solder flowing into the wire past the crimp band will be almost negligible. Crimp system design is such that a well done crimp will result in preventing moisture and oxygen from entering the crimp, preventing corrosion from occurring.

The following picture illustrates this.

Soldering of Crimp Terminal

Using solder with a crimp from a lesser quality crimp tool as has been illustrated in the picture Tale of 2 Crimps, can result in a better crimp joint as solder may flow into the wire past the crimp band.

When using solder on a wire crimp, be careful to only apply enough solder to flow into the wire where it is crimped. Solder that flows past the wire crimp will form a hard spot that can fail when subject to vibration. It is further recommended that if solder is used, the preference is to use non-insulated crimp terminals rather than insulated crimp terminals.

A second concern is when soldering, too much heat and/or solder flowing into the wire insulation can cause the wire insulation to shrink away from the crimp terminal. This is to be avoided if possible.

Lastly, when soldering a crimp terminal, solder wicking cause the multi-strand conductors that have high flexibility and stability against vibration to become, in essence, a solid wire that degrades both of the performance characteristics mentioned.

Another comment found on-line is that soldered crimp terminals can lose some ability to withstand flexing and vibrations because of solder embrittlement of the copper wire strands and/or due to solder flowing into the stranded copper wires.

Conclusion

This ends the rather long and involved dissertation on crimp systems. I trust that it has been informative, and possibly of help to you, the reader. There is additional information regarding crimp systems, but I will leave some of the mystery associated with crimping up to you to investigate.

On to the next installment in this long series.

Cheers

 

[mcgovern61]

:thanks: Are you going to add a section on working with the OEM connectors?

 

[Rednaxs60]

Good suggestion for another section. Will do.

Cheers

 

[Rednaxs60]

Gerry - Can do a post on the OEM connector now that I have a good crimp tool as I mention. Will be using some of your pictures to illustrate.

Have also started an article regarding wiring, where and how to connect, and types of wire covering, tape - plastic/abrasion resistant, wire size - SAE/AWG, and much more.

There is a lot of information available regarding electrical systems and what goes into them.

Cheers

 

[mcgovern61]

Looking forward to it! Let me know if there are any specific pictures you need from my work and I can point you to them in the gallery. :yes:

 

[brianinpa]

Great stuff Ernest!

 

[pidjones]

I would also appreciate an article on cleaning existing connectors that have begun to oxidize, but have not yet overheated or shown other failures.

 

[Rednaxs60]

Working on a post regarding the OEM connectors. I have been perusing the internet and there is a wealth of information, including newer best practices. I have also found web sites that get into the weeds on crimping, how the crimp is made, what cross sections look like and why, and a lot more. This is actually a very involved topic.

One web site I found was in response to learning about crimping, and in doing so it changed his whole way of doing business. There are acceptable practices, and better practices that are in the long run, IMHO, more cost effective.

Should have the new follow-on thread posted soon.

Cheers

 

[desertrefugee]

It's also pretty easy to overthink it.

As a 35 year electrical engineer, I've spent a lot of time in the lab and have seen, probably, hundreds of different crimp styles, connectors, etc.

Essentially, the bottom line boils down to - appropriately sized (and type) contacts for the wire being used (gauge/stranded/solid) and the correct crimper or die for the contacts being employed. After that, it's pretty much down to proper technique (as Earnest has detailed) with correct stripped wire length and preparation.

Not really rocket science, just paying attention to the details.

 

[backlander]

Excellent thread Earnest.

 

[kerryb]

Wow! Thank you for a very informative lesson. I have been using bullet connectors from.. https://vintageconnections.com with their high quality crimping tool (spendy, but worth it), but you have filled in a lot of blanks in my knowledge base. Now I can tell the difference in the many crimp tools that have found their way into my tool drawer.

all part of the adventure.

 

[Rednaxs60]

I've learned a lot from doing these posts, and my understanding of the various aspects of the electrical system, wiring, connectors, tools and the likes has increased as well.

The basics are to invest in the best ratcheting crimp tool with interchangeable crimp dies that you can. Even a lesser grade ratcheting crimp tool is better than an inexpensive one from the local hardware store, and will do a better job.

Use the proper size crimp terminal for the job. Lesser quality crimp terminals will not be consistent in size quality, pay a little more and the end result, and longevity will pay for the added few sheckles.

Get a good wire stripper so you won't nick the wire strands, or remove wire strands reducing the size of the wire.

Use the best quality crimp terminals you can afford, will pay off in the long run.

If possible, avoid using the following:

House wire nuts have no place on a bike wire connections. The spade crimp terminals can fall of a terminal if the terminal comes loose.

Use proper size ring crimp terminals. If you use one that is too large for the application, change as soon as possible.

Use quality wire. Marine grade wire that is tinned throughout is a good alternative to automotive wire.

Use of a good quality ratcheting crimp tool resulting in a good quality crimp does not need to be soldered.

Soldering of wires that are not subjected to excess vibration or bending forces and will have shrink tube used to insulate the solder joint is good. If vibration or bending is expected, use a crimp terminal.

If you have to remove the OEM single and multi pin connectors, recommend replace with same. This type of connector is good for new wire installs as well. This is also where the ratcheting crimp tool with exchangeable crimp dies will come in handy.

Be consistent in how you modify, install new wiring. It'll look good and perform well.

Just a few points/thoughts for consideration.

Cheers

 

[desertrefugee]

Ernest, this is a good, comprehensive overview of the crimping process and this community is better for having it here. It's good that you've taken the time to collect and compile these notes and photos. I hope my comments above weren't taken the wrong way. In retrospect, I should have stated it differently.

My intent was simply to emphasize the key points - that most issues with crimps could be avoided simply by combining appropriately selected bits, pieces and tools: crimp type/size, wire and tool. Of course, proper technique is essential, as well.

One last note: even though I've build all manner of test cables, prototyped equipment and crimped thousands of wires over the years, I still give each and every crimped contact a good tug just as a final sanity verification before moving on.

 

[Rednaxs60]

desertrefugee » Today, 8:18 am[/url]":34sb57s4]
Ernest, this is a good, comprehensive overview of the crimping process and this community is better for having it here. It's good that you've taken the time to collect and compile these notes and photos. I hope my comments above weren't taken the wrong way. In retrospect, I should have stated it differently.

My intent was simply to emphasize the key points - that most issues with crimps could be avoided simply by combining appropriately selected bits, pieces and tools: crimp type/size, wire and tool. Of course, proper technique is essential, as well.

One last note: even though I've build all manner of test cables, prototyped equipment and crimped thousands of wires over the years, I still give each and every crimped contact a good tug just as a final sanity verification before moving on.

Not at all, I thought I was amplifying what you mentioned. Always good to have constructive comments.

I post this information because I am interested in it, and trying to find information on any one subject in one spot is difficult at best. I also like to try and emulate the "experts" when it comes to installations and such.

I will be redoing my electrical system to ensure consistency in crimp terminals, wire colour - going to use yellow for my ground wires similar to the direction the boating industry has gone, need to look at the relay requirements - already have three may need more and put together a secondary wire harness.

Maybe I can put these articles together and apply for the Pulitzer literary prize for reality fiction.

Cheers

 

[dan filipi]

Rednaxs60 » Today, 10:50 am[/url]":23tq6heh]

desertrefugee » Today, 8:18 am[/url]":23tq6heh]
Ernest, this is a good, comprehensive overview of the crimping process and this community is better for having it here. It's good that you've taken the time to collect and compile these notes and photos. I hope my comments above weren't taken the wrong way. In retrospect, I should have stated it differently.

My intent was simply to emphasize the key points - that most issues with crimps could be avoided simply by combining appropriately selected bits, pieces and tools: crimp type/size, wire and tool. Of course, proper technique is essential, as well.

One last note: even though I've build all manner of test cables, prototyped equipment and crimped thousands of wires over the years, I still give each and every crimped contact a good tug just as a final sanity verification before moving on.

Not at all, I thought I was amplifying what you mentioned. Always good to have constructive comments.

I post this information because I am interested in it, and trying to find information on any one subject in one spot is difficult at best. I also like to try and emulate the "experts" when it comes to installations and such.

I will be redoing my electrical system to ensure consistency in crimp terminals, wire colour - going to use yellow for my ground wires similar to the direction the boating industry has gone, need to look at the relay requirements - already have three may need more and put together a secondary wire harness.

Maybe I can put these articles together and apply for the Pulitzer literary prize for reality fiction.

Cheers

Well, I don't know about that but we could at least make them stickies :yes: