Working with electrical connectors, help needed

[Dr.Jeff]

I had to put my rewiring projects on hold while I was waiting for some new electrical connectors to arrive (shipping took forever). I decided to try a type of wire splice that is recommended by many top professionals for a clean and secure splice without a lot of bulk. The connectors are commonly referred to as "U" type crimp terminals, but apparently the proper name for them is "454" type splices. They come in various sizes for different gauge wires, with a letter code to distinguish them:

Essentially they are a "crimp on" item, similar to the common crimp terminals. The wires are laid over one another, and the terminal is 'wrapped' around them by crimping it tightly:

I like that they can accommodate two different gauges of wire or even a different number of wires in the same splice (as above). Heat shrink is used to insulate the splice.

The crimping tool for them appears to be the same as for other 'double crimp' (Euro style) terminals, where there are two crimps - one on the wire and one on the insulation:

They finally arrived today and I began experimenting with installing them. However I quickly learned the crimp tool is NOT the same as with other terminals. The double crimp style connectors have two sizes of collar, one larger to fit over the insulation:

Therefore the jaws in the crimp tool have a stepped, two-size shape to accommodate those two collars in a single crimping action. This step will not allow the "U" (454) terminals to fold over correctly, and they just mangle it. Here is what the proper tool looks like:

Notice how the jaw is straight across rather than stepped (red lines):

This subtle difference seems to have a huge affect on their ability to crimp these terminals. So the crimpers I have will not work and a new set must be purchased. No only a bit expensive but yet another shipping delay before I can finish my wiring projects.

Hopefully someone out there has used this "U" (454) type of splice terminals and can offer some insight to help me with them? I searched online but this type of terminal is not common and I could not find any information on using them. Is there a trick to it? Do I need the specific jaws just for these splices?

 

[dnudelman]

I just completed extensive splicing on my 71 850 coupe wiring harness. The donor harness was off an 850 spider. That makes the wire I was using only 5-10 years older than your X's. After stripping the wire, I dipped it in a vinegar solution, then baking soda. Added a dip in flux, each wire was tinned with rosin core soldier. I crimped the ends in an uninsulated barrel butt connector and soldiered the whole assembly. Heat shrink tubing on top. Initially its a bit slower than a pure crimp connector solution, but once you get going, it's pretty quick. You might find your wire has some level of corrosion even under the insulation. A good gun is a man's best friend.

 

[kmead]

I had to put my rewiring projects on hold while I was waiting for some new electrical connectors to arrive (shipping took forever). I decided to try a type of wire splice that is recommended by many top professionals for a clean and secure splice without a lot of bulk. The connectors are commonly referred to as "U" type crimp terminals, but apparently the proper name for them is "454" type splices. They come in various sizes for different gauge wires, with a letter code to distinguish them:
View attachment 51261

Essentially they are a "crimp on" item, similar to the common crimp terminals. The wires are laid over one another, and the terminal is 'wrapped' around them by crimping it tightly:
View attachment 51262
I like that they can accommodate two different gauges of wire or even a different number of wires in the same splice (as above). Heat shrink is used to insulate the splice.

The crimping tool for them appears to be the same as for other 'double crimp' (Euro style) terminals, where there are two crimps - one on the wire and one on the insulation:
View attachment 51264

They finally arrived today and I began experimenting with installing them. However I quickly learned the crimp tool is NOT the same as with other terminals. The double crimp style connectors have two sizes of collar, one larger to fit over the insulation:
View attachment 51265
Therefore the jaws in the crimp tool have a stepped, two-size shape to accommodate those two collars in a single crimping action. This step will not allow the "U" (454) terminals to fold over correctly, and they just mangle it. Here is what the proper tool looks like:
View attachment 51266
Notice how the jaw is straight across rather than stepped (red lines):
View attachment 51267

This subtle difference seems to have a huge affect on their ability to crimp these terminals. So the crimpers I have will not work and a new set must be purchased. No only a bit expensive but yet another shipping delay before I can finish my wiring projects.

Hopefully someone out there has used this "U" (454) type of splice terminals and can offer some insight to help me with them? I searched online but this type of terminal is not common and I could not find any information on using them. Is there a trick to it? Do I need the specific jaws just for these splices?

In the MegaSquirt thread he used these same connectors to join wires on a number of his joints. I don’t recall the tool he used.

 

[Dr.Jeff]

I just completed extensive splicing on my 71 850 coupe wiring harness. The donor harness was off an 850 spider. That makes the wire I was using only 5-10 years older than your X's. After stripping the wire, I dipped it in a vinegar solution, then baking soda. Added a dip in flux, each wire was tinned with rosin core soldier. I crimped the ends in an uninsulated barrel butt connector and soldiered the whole assembly. Heat shrink tubing on top. Initially its a bit slower than a pure crimp connector solution, but once you get going, it's pretty quick. You might find your wire has some level of corrosion even under the insulation. A good gun is a man's best friend.
View attachment 51269

I've soldered wire connections in the past. But I want to try these crimps instead. For one thing I am not good at soldering...guess it just isn't my thing. But also I've read many sources that feel these tiny crimps are a highly preferred method. As @kmead siad, they are the choice of the ECU instruction manuals. I'm not 100% sure why. I think partly because they create a very tiny, clean splice. No bulky butt-splice tube, no long end-to-end terminal splice, no heavy insulation. The resultant splice looks almost like there was no joint at all (relatively speaking). And as I mentioned earlier they allow multiple wires and different gauge wires to be joined nicely. But I also think there may be a bit more to them than that. Soldering can have its own problems in particular situations. I realize that has been a very long ongoing battle - to crimp or solder. And I've done both and see pros and cons for both. Regardless I'd really like to see how well these work, but I'm having difficulty learning the proper technique (or tool?) to install them.

The smaller size "U" splices (for thin gauge wires) aren't quite as difficult. I have a basic, non "ratcheting" crimping tool that is intended for those tiny "Molex" type connector pins. The jaws are the same basic design as the ones for the 'double crimp' (Euro) type - meaning they fold the terminal "ears" over into the wire. But they don't have the two-size stepped openings, so they don't mangle the "U" terminal like the ratcheting ones do. However they are also quite small and narrow. While the smaller size "U" terminals will fit in them, the jaws are still too narrow to fully crimp the full length of the splice.

I think with the right jaws in my ratcheting crimp tool they will work. But I cannot find just the jaws in that style - only the entire ratcheting tool with those jaws (and only one choice for that). Therefore before I invest in yet another pair of crimping pliers I'd like to find some confirmation on how to do it.

Along the same lines regarding crimping tools. The ratcheting crimpers that I have will accommodate up to 14 gauge wires/terminals. But the jaws do not have opens large enough to crimp terminals made for 10 gauge wires. I've searched for jaws with a larger capacity, and purchased a set that were described as handling 10 gauge wires/terminals. But they did not so I returned them. Funny because they make the terminals for 10 gauge wires, so they must make the crimping jaws for them.

 

[dnudelman]

Soldiering is easy if you have cleaned the wires and dip the ends in flux. Tin the wires and tap to drop the excess. As I said, I used a bare crimp butt connector to hold the tinned wired together and heated it up until everything melts together.

 

[Dr.Jeff]

In the MegaSquirt thread he used these same connectors to join wires on a number of his joints. I don’t recall the tool he used.

Ya, that's one of the places where I've read about them. Also some ECU makers in Europe recommend them. They seem to be more popular over there than here, which is why I'm hoping we have members with experience using them. I can find pictures of the completed crimp, and even some pics depicting the use of a ratcheting type crimper with them. But only one crimper (Iwiss 0560) that appears to be made for these terminals. Are they that uncommon? And that unique to install?

 

[lookforjoe]

I like those. I often have to splice several wires of differing gauge - these would fit the bill nicely.

Where did you buy them (in bulk?) Aliexpress?

Why can't you crimp them progressively - flipping the crimp pliers over to use only the one size that is appropriate? I appreciate that may be fiddly, but I don't see why it wouldn't work.

I avoid soldering any wires that have to be situated in the engine bay or external to the cabin. The solder joints can suffer from fatigue.

 

[Dr.Jeff]

I like those. I often have to splice several wires of differing gauge - these would fit the bill nicely.

Where did you buy them (in bulk?) Aliexpress?

Why can't you crimp them progressively - flipping the crimp pliers over to use only the one size that is appropriate? I appreciate that may be fiddly, but I don't see why it wouldn't work.

I avoid soldering any wires that have to be situated in the engine bay or external to the cabin. The solder joints can suffer from fatigue.

They are from AliExpress. A hundred of each size for less than $2, or a kit with a selection of sizes for less than $5. Here is just one quick example, but shop around:

1.85US $ |400ppcs Dj454 0.5-6.0mm2 U-shaped Copper Wire Crimps Terminal Cold Pressing Connectors Cable Lug For Wire Tab Terminal - Terminals - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

I'll have to play with the crimpers more to see what can be done. Your idea of doing half at a time (flipping the crimper over) is good, and a bit tricky because the terminal is one piece of metal so it doesn't want to curl over evenly when done in segments. But maybe with a little more practice I'll figure out a method. Especially on the smaller size splices it should work. The bigger ones are much more difficult.

I've been looking at the crimpers more and I see they use a very similar type of one for some special "solar power" connectors. Those crimpers are more available and affordable. I can get just the jaws for a few $ and try them in my crimpers. The good thing is they should also be able to work on larger terminals for 10 gauge wires.

 

[dcioccarelli]

I just completed extensive splicing on my 71 850 coupe wiring harness. The donor harness was off an 850 spider. That makes the wire I was using only 5-10 years older than your X's. After stripping the wire, I dipped it in a vinegar solution, then baking soda. Added a dip in flux, each wire was tinned with rosin core soldier. I crimped the ends in an uninsulated barrel butt connector and soldiered the whole assembly. Heat shrink tubing on top. Initially its a bit slower than a pure crimp connector solution, but once you get going, it's pretty quick. You might find your wire has some level of corrosion even under the insulation. A good gun is a man's best friend.
View attachment 51269

I think the soldering vs. crimping subject has come up a few times. I'd consider myself a good solderer but I still crimp automotive connectors. The wicking of the solder causes a fatigue point when combined with vibration. Almost all modern connections are crimped at the factory. This article explains the subject well:

Should you Crimp or Solder when repairing your vehicle? - Millennial DIYer

Whether it's better to crimp or solder when doing electrical work on motorcycles or vehicles is controversial. Here's why and what's best.

millennialdiyer.com

 

[dnudelman]

I think the soldering vs. crimping subject has come up a few times. I'd consider myself a good solderer but I still crimp automotive connectors. The wicking of the solder causes a fatigue point when combined with vibration. Almost all modern connections are crimped at the factory. This article explains the subject well:

Should you Crimp or Solder when repairing your vehicle? - Millennial DIYer

Whether it's better to crimp or solder when doing electrical work on motorcycles or vehicles is controversial. Here's why and what's best.

millennialdiyer.com

Lots of straw men in this article, Ifs and Buts and then makes a generalization. YMMV

 

[Dr.Jeff]

I played around with the crimp style splices more today. I can see where having the right crimper will make a big difference.

The larger ones are more difficult to install. They require quite a lot of energy to make them fold over on themselves. Without the proper tool I have not been able to successfully install them.

The smaller ones are easier. If you have enough room (like when assembling things on the workbench) then you can do as @lookforjoe suggested and crimp one half, then flip it around and crimp the other half. But even then it is a bit tricky and easy to mess it up in the process. They are not like crimping the more common double-crimp terminals; the 'tangs' on those are much smaller and therefore much easier to successfully fold over.

Also the size of the "U" type splice terminal you select makes a big difference on the outcome in terms of how well it secures the wires. So having a variety of sizes is very helpful.

I will order the jaws that I found listed for a similar "solar" application crimp terminal and see how it goes. For anyone considering these "U" splices I'd suggest buying the kit that includes the tool along with an assortment of terminal sizes.

 

[lookforjoe]

I played around with the crimp style splices more today. I can see where having the right crimper will make a big difference.

The larger ones are more difficult to install. They require quite a lot of energy to make them fold over on themselves. Without the proper tool I have not been able to successfully install them.

The smaller ones are easier. If you have enough room (like when assembling things on the workbench) then you can do as @lookforjoe suggested and crimp one half, then flip it around and crimp the other half. But even then it is a bit tricky and easy to mess it up in the process. They are not like crimping the more common double-crimp terminals; the 'tangs' on those are much smaller and therefore much easier to successfully fold over.

Also the size of the "U" type splice terminal you select makes a big difference on the outcome in terms of how well it secures the wires. So having a variety of sizes is very helpful.

I will order the jaws that I found listed for a similar "solar" application crimp terminal and see how it goes. For anyone considering these "U" splices I'd suggest buying the kit that includes the tool along with an assortment of terminal sizes.

Can you be more specific with what is "large" or 'small" - 10ga? 20ga? somewhere in-between?

 

[lookforjoe]

They are from AliExpress. A hundred of each size for less than $2, or a kit with a selection of sizes for less than $5. Here is just one quick example, but shop around:

1.85US $ |400ppcs Dj454 0.5-6.0mm2 U-shaped Copper Wire Crimps Terminal Cold Pressing Connectors Cable Lug For Wire Tab Terminal - Terminals - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

I'll have to play with the crimpers more to see what can be done. Your idea of doing half at a time (flipping the crimper over) is good, and a bit tricky because the terminal is one piece of metal so it doesn't want to curl over evenly when done in segments. But maybe with a little more practice I'll figure out a method. Especially on the smaller size splices it should work. The bigger ones are much more difficult.

I've been looking at the crimpers more and I see they use a very similar type of one for some special "solar power" connectors. Those crimpers are more available and affordable. I can get just the jaws for a few $ and try them in my crimpers. The good thing is they should also be able to work on larger terminals for 10 gauge wires.

Thanks for bringing this up. I've ordered a pair of the IWISS IWS-0560 tool & an assortment of the 454 terminals.

 

[Dr.Jeff]

Can you be more specific with what is "large" or 'small" - 10ga? 20ga? somewhere in-between?

Sorry, I should have been more specific on the sizes. Sounds like you already ordered a selection of them, but I'll add more info for anyone else that might be interested.

The way these splices wrap around the wires when crimped, the overall size of the terminal will need to be different for various applications. Including the gauge(s) of the wires, how many wires, what combination of various numbers and gauges of wires that you are splicing. So there isn't a one-for-one corresponding size for a given use, it depends. But if you try to use a splice terminal that is too large then it won't crimp over the wires securely, they will be loose and can pull out. If you try to use a splice terminal that is too small then it won't reach completely around the wires fully.

As a general guide there are something like 5 or 6 different sizes of them to choose from. The first pic I showed in post #1 are the most common three sizes (454 A, B, and C). The smallest one will generally be for finer wires, like often found on LED bulbs (22 gauge?). The larger of the three should be able to splice two or possibly three 10 gauge wires (I will have to wait for the right tool to verify that). They have even bigger ones but I don't think there are any practical uses for them on a car. If you are dealing with huge wires then I think these may not be the best way to splice them. They also have even smaller ones but those would be very difficult to use - they would be so tiny I don't see how you could effectively use them. So I think those three sizes shown (454 A, B, and C) should be a good selection for most uses. And those seem to be what many of the "kit" assortments include.

The tool seems to be an important part of using these crimp splice terminals. As I described earlier, these terminals work very similar to the more common double-crimp (Euro) terminals, but not the same. And the tool used for double-crimp terminals isn't very effective for these splices. You could make it work for the smaller size splice, but even that won't be pretty. Likewise trying to use other various tools did not work well, at least in my experience (maybe someone else can find a better method). But look closely at the tool offered. After a lot more searching I've come across a couple of them and some seem to be made for different sized terminals. What I mean is some tools may not have the jaw openings large enough for the larger splices, and others may not have a small enough opening for the smaller splices. I'm still looking at options to see what the best choice might be for all three sizes (sorry I had to stop looking to take care of other matters so haven't finished yet).

Hope that adds a little more info for you.
@lookforjoe, please let me know what you get and how it works for you. This is something new to me and I'm still learning.

 

[Dr.Jeff]

Here are the options I've found for crimping tools to use with these "U" (454) splices.

Earlier I referenced one, the "Iwiss 0560". This crimper has the jaw openings to fit four sizes of the terminals, from .2mm2 to 6mm2 (more on the sizes later). It runs about $30, shipped:

27.86US $ 25% OFF|Crimping Buckle 454a/b/c Copper Buckle Crimping Pliers, U-type/c-clamp Wire And Wire Buckle Crimping Tools - Pliers - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

I also found another version from another manufacturer, the "HS-2546B". It fits three sizes of terminals, from .5mm2 to 6mm2. Sells for about $16, shipped:

15.72US $ 15% OFF|Colors Crimping Pliers Professional U Shape Copper Wire Terminals Connectors Ratcheting Crimper Tool for 454A 454B MC4|Pliers| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Looking at it, and based on my other crimp tools, I suspect it is a lower quality tool than the first one. Specifically the jaws that do the actual crimping.

A third possible option is to buy only the "jaws" that fit an existing crimp tool handle. The tools are intended to be versatile by allowing interchangeable jaws to be used for various types of crimp terminals. There are a few different models of crimp handles (frame) and each utilizes a specific design of jaws. For example the second tool I referenced is called the "HS-2546B". "HS" is the general style of handle (tool frame), and "2546B" is the particular jaw set that it comes with. So if you already own a "HS" series crimp tool then you could buy just a set of "2546B" jaws to use in your existing tool. Jaws typically run about $5 a set.

Unfortunately I did not find the "2546B" jaws offered separately for the "HS" tool. As I said previously, these style of crimp terminals don't seem to be very common, so finding the correct tool is difficult. Furthermore, while I own several different crimping tools, "HS" is not one of them. I do have a "SN" crimp tool (another design of handle), but once again I did not find a set of "454" jaws specifically for it either. But I did find a set of jaws to fit yet another style handle, the "JX" series. Apparently the "JX" is more commonly used in the solar energy industry. That industry uses the same style of terminals so the corresponding crimping tool is offered. And better jet, they sell the jaws for it separately...the "JX-2546". According to what I've read the "JX" jaws can be used in the "SN" tool handle if a spacer plate is added (also available separately). Sounds a little complicated but really it isn't. Basically the width of the jaws (where they mount into the handle/frame) is narrower, therefore the need for a simple spacer.

Since I already own a bunch of different crimper tools I wasn't in a hurry to buy yet another one. It has become a bit of a pet peeve for me, with all of the different 'proprietary' designs of crimpers needed. So I ordered the "JX-2546" jaws to adapt to my "SN" crimp tool. They are around $5, and have three openings to fit terminals from .5mm2 to 6mm2:

2.32US $ |2546 AWG Alloy Steel Solar Connector Terminals Die Wire Crimper Jaw Ferrule Mold Crimping Pliers Accessory Tool|Pliers| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

That is what I've found available to utilize the "454" splice terminals. Getting back to the sizes. I mentioned some tools have three openings and at least one has four. Those openings correspond to the size of "454" splice used. There are at least 5 or 6 sizes available, but really only two or three are the most common sizes for automotive use. Look at the pic I posted earlier:

The first one (454A) is for wires from .5mm2 to 1.5mm2. That is a metric reference to wire gauges. It denotes the cross section area of the wire (hince the squared number). There are charts to cross reference that into regular wire gauges:

http://www.sapiensman.com/conversion_tables/imagenes/annealed_copper.jpg

From that you can see why the three splice sizes shown in the picture will be most common for cars. But keep in mind the splice sizes are for one wire spliced to one other wire, both of the same gauge. If you have three (or more) wires to join, or two (or more) different gauges of wires to join, the the choice of crimp size will differ.

Looking back at the tools I listed. The first one (Iwiss) will accommodate .2 mm2 (24 gauge) wire (I think there are called "454 ST" terminals) to 6 mm2 (10 gauge) wire ("454 C" terminals). The others accommodate .5 mm2 (20 gauge) wires ("454 A") to 6 mm2 ("454C"). If for any reason you need even larger splices then you will need yet a different crimp tool, as none of these go that big.

A note about crimp tools and sizes. I have found there is a lot of variance between different manufacturers in what they consider each size to be. You would think it is standardized but it isn't. For example I purchased a set of jaws that were specified for "double-crimp" style terminals with 6mm2 (10 gauge) wires. However when they arrived I found even the largest opening in those jaws were way too small to fit my 10 gauge terminals. I don't know why there is so much variation, but just be aware that everything I've reported in this post is based on the specs shown in the listings. I have not received the new tools I ordered yet so I cannot verify they will work correctly.

 

[Dr.Jeff]

I received the new jaws for my crimp tool (link below), to use with these "U" splices. They were intended for a slightly different model of crimper ("JX", mine is a "SN"), so I had to make a simple pair of spacers. Basically a 2mm thick piece of flat stock to fit in between the side of the jaws and the frame of the tool (the SN frame is wider than the JX). The three sizes of openings on these jaws fit the most common sizes of splices - 454 A, B, and C. They work perfectly, much better than when I tried to use a standard set of crimp jaws. Makes perfect crimps on the "U"(454) splices. So you definitely need the correct tool to use them. @lookforjoe ordered the crimp tool made for them, as shown in a earlier post (post #15). Since I already own several types of crimp tools I decided to try just the jaws:

2.32US $ |2546 AWG Alloy Steel Solar Connector Terminals Die Wire Crimper Jaw Ferrule Mold Crimping Pliers Accessory Tool|Pliers| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[lookforjoe]

My tool & crimps arrived tonight - I'll take some pic of it tomorrow

 

[jimmyx]

The Pertronix is a little pricey, but is my go-to crimp tool of choice when perfection is required.

Pertronix Launches Wiring Tools

We’ve been using Pertronix products for decades. From its famous under cap Igniter ignition conversion kits to its plug wires and coils, we’ve pretty much insta

www.motortrend.com

 

[lookforjoe]

I don't actually need to use the tool right now - but the crimp area is certainly deep enough to properly roll the crimp. I probably could have bought the inserts to use in the other crimp tool I bought from the same company....

 

[Dr.Jeff]

The Pertronix is a little pricey, but is my go-to crimp tool of choice when perfection is required.

Pertronix Launches Wiring Tools

We’ve been using Pertronix products for decades. From its famous under cap Igniter ignition conversion kits to its plug wires and coils, we’ve pretty much insta

www.motortrend.com

Nice. That is the same design as the crimpers that @lookforjoe and myself have and are discussing here. They are great and having the choice of different interchangeable jaws is a real plus; it seems every type of connector uses proprietary terminals and require a specific crimper. This way you don't need a whole new tool for each type of connector, just swap the jaws.