Joining wires

Interesting debate, terminals v solder. It has been a while since I have had to do a wire repair but I always thought solder and heatshrink was the way to go. Maybe not.
I used to use connectors, anything from the plastic crimp style to those bare metal ones mentioned above. The bare ones (often with clear rubberised insulation you'd slide over after crimping) worked better, except I couldn't reliably get the tangs to fold over perfectly to grip the wire. I'd look at factory terminals/connectors and wonder what they used to get them so perfect. Mind you I had just pliers back then.
The coloured plastic crimp connectors drove me crazy. Even after I bought a you-beaut crimping tool from Jaycar. Could never trust them, often in a bunch of wires repaired I'd find a wire hanging, having easily pulled out of the connector. No matter how careful I was, there'd always be one. That's what turned me to solder and heat shrink.
Anyway, thanks for the info on solder wicking, has made me reconsider any future wire repair.
 

DoubleChevron

Real cars have hydraulics
PeterT, I can confirm your solder joins on the 306 XSi door harness have failed, and that leads directly into why there is such a debate over crimp vs solder.

You can't solder a wire that has movement (eg: into doors and boots). You are creating a spot that will not flex. Much like you can't just weld up a crack. I have no doubt any join in a door or boot harness (where you create something that can't bend) will soon break. This includes crimp on connectors.

You would need to replace the wire with a wire designed to flex ..... but splice this new wire back in back where it can be firmly fixed down.
 

PeterT

1000+ Posts
PeterT, I can confirm your solder joins on the 306 XSi door harness have failed, and that leads directly into why there is such a debate over crimp vs solder.
Fair call. That was a bodge just to sell the car. The car was a bonus anyway, wrapped around a Quaife ATB.
 

The Gonz

Member
Should you solder a crimped connection in the belief it makes it more reliable you have created a situation where the solder 'wicks' back up the wire from the connection and each strand of what was multiple flexible strands of copper terminates into a solid block of solder that should the wire flex each strand will break at the same spot. Note that over crimping (too much force) will cause a similar point of failure.
Alex, I'm not disagreeing. However, if vibration or expansion and contraction is a problem for a solder joint, the problem is not the solder but the wiring design. Even discreet components need to be soldered properly using expansion bends in their leads, and my aircraft wiring is fastened at the loom and then given appropriate radius before getting to the solder joints. Crimps are just a quicker and more convenient way, but not the best by other measures.
 

schlitzaugen

1000+ Posts
I've never owned a crimper that'll do a connection I can't pull apart ........... I've heard that solder will crack. I've never experienced it though :)

You need to get some serious crimping tools. Jaycar, Altronics, etc don't have them. Look on RS components and you'll see they are 400$ and up. That is what the factory uses to get those superb crimps you see. No, they don't use that they use a machine with hydraulic actuation, but the dies doing the actual crimping are probably the same or similar.

Get yourself a Deutsch crimper (from Deutsch or Knipex) they are the cheapest standard of proper crimper. I think I paid just under 300 for mine, but like I said, if you want anything else they are above 400$. Deutsch is good enough for the mining industry so I call that good. Plus you can get the terminals by themselves (see RS Components) in any size you want (check what sizes your crimper will do) and the connectors (housings - plugs and sockets) too. In all sorts of versions, all water proof plus panel mounts, brackets, goosenecks, boots, right angle, straight, flush etc. you name it. They are not cheap but they are forever reliable.

I used to crimp and solder Deutsch , the soldering is contained inside the terminal, the wire has no solder on it past the terminal and the silicone seal serves as the support so if the wire is wiggled and moves, it only moves up to the silicone seal, not behind it where the soldered joint is. I have also used large glue lined heatshrink tube over the plastic casing just to make double sure no ingress of any kind is possible including petroleum derived chemicals of any kind. Works. In recent times I have started to trust Deutsch enough that I don't solder anymore, just crimp and it's done. I also use silicone wire, very expensive but practically impervious to anything except for knife. Won't even burn or melt, so ideal for engine bay wires. For the current they are capable of, size is also better than vinyl insulated. A silicone wire crimped with the correct tool and with sealed Deutsch connectors at both ends will not let you down.

Crimping is not that easy for the home gamer. As I mentioned above, you enter a painful world with cheap crimpers (I have an entire stash of junk) or splash out on something good, but that comes with its own problems. Every car manufacturer has their own terminals, plugs, sockets and it never ends! There's more standards than digital camera .RAW file formats!! Which one to get?! And will you then change all the connectors on the car to that standard? And will you find the terminals?

That is why I chose Deutsch. It's universal, sealed, well represented everywhere, parts readily available, relatively cheap and original crimpers are not a fortune to buy. They are easy to take apart or pull individual wires with terminals on out and put back in with no special tools. Extremely convenient if you know what it means to try and take the wires out of a Toyota or Honda plug. Plus their run of the mill contacts are silver nickel or you can get the top of the line gold ones! Yeah, baby! Don't tell your wife the car is getting gold terminals though.

Which is where soldering comes in. Solder joints are fragile at the transition point between the solder and the bare wire. Copper work hardens easily so if there is a preferred flex point where it will always flex, that point will work harden and break. Soldering creates one such point. The soldered part is stiff and doesn't flex, the bare wire without insulation is now the preferred flex point. Use heatshrink, generously extending either side of the solder joint and you won't have problems.

I used to use a NASA standard solder joint (see here: https://i0.wp.com/cdn.makezine.com/uploads/2012/02/western-union-or-linemans-splice.jpg?resize=514,580) with heat shrink tube. Didn't know it was called that, I came up with it out of despair. Don't worry about the picture being with single wire, it works very well on multistrand.

Silicone wire is probably the best (but the most expensive, of course) here too. It uses so many strands of copper and it is so flexible (ever heard of "wet noodle"?), it is difficult to work harden any particular strand of wire in it simply because there's so may of them and they're so fine. It is therefore unlikely you're going to bend the same wire the same way twice (which is how work hardening happens). It does happen eventually but it will take a long time. If you use heatshrink you will get a joint that will outlast the car and most likely you too.

And if you have solder wick past where you want it to, your technique is not great. I use a high power iron with large chisel tip. I hold it inverted in a stand. Put some solder on it to create a small puddle like a blob and then come in with the bare wire and insert it in the blob as far in as you want it tinned and pull it out. Be quick, not lighting fast but don't dwell. You need to be in and out before the flux loses its efficiency. There will be no excess tin, no wicking no nada. If you have excess tin, refresh the blob, come in with the wire again, the excess will be retained by the blob. If you have sharp spikes you're too slow (left the blob dwelling too long and the flux has evaporated) and/or the iron is not hot enough. Practice.

After that, you can trim it back if needed to how long you want it tinned if you overshot.

And you can crimp it at whatever point you want to crimp it. You can crimp it so the tinned portion doesn't project out of the terminal. And you can add solder to the join after crimping. Again, because the wire is tinned already you can do it in a fraction of a second (tin heats quickly and spreads the heat evenly) and there will be no wicking because the rest of the wire is not hot enough yet to suck the tin along.

I know it's hard when you have two wires barely reaching each other poking out of holes at opposite ends of the dash in the footwell, but believe me, it is possible.

And if it's not possible, just put a connector in line. It will be easier to service!

As for the original post gizmo, I gave up on any auto terminals, just too much trouble. When something needs fixing, it's converted to Deutsch. There are OEM senders, etc that come with their own (generally Bosch) connectors moulded as part of the casing, so I keep a selection of Bosch sockets/plugs for those situations. Bosch connectors are not bad either, so I don't have a problem with those. There are also connectors moulded into globe holders in indicators, headlights and such. If I can solder pigtails I can terminate with a Deutsch plug and pot the soldered end in situ I do that. If not, I don't yet have a solution.
 
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DoubleChevron

Real cars have hydraulics
You need to get some serious crimping tools. Jaycar, Altronics, etc don't have them. Look on RS components and you'll see they are 400$ and up. That is what the factory uses to get those superb crimps you see. No, they don't use that they use a machine with hydraulic actuation, but the dies doing the actual crimping are probably the same or similar.

Get yourself a Deutsch crimper (from Deutsch or Knipex) they are the cheapest standard of proper crimper. I think I paid just under 300 for mine, but like I said, if you want anything else they are above 400$. Deutsch is good enough for the mining industry so I call that good. Plus you can get the terminals by themselves (see RS Components) in any size you want (check what sizes your crimper will do) and the connectors (housings - plugs and sockets) too. In all sorts of versions, all water proof plus panel mounts, brackets, goosenecks, boots, right angle, straight, flush etc. you name it. They are not cheap but they are forever reliable.

I used to crimp and solder Deutsch , the soldering is contained inside the terminal, the wire has no solder on it past the terminal and the silicone seal serves as the support so if the wire is wiggled and moves, it only moves up to the silicone seal, not behind it where the soldered joint is. I have also used large glue lined heatshrink tube over the plastic casing just to make double sure no ingress of any kind is possible including petroleum derived chemicals of any kind. Works. In recent times I have started to trust Deutsch enough that I don't solder anymore, just crimp and it's done. I also use silicone wire, very expensive but practically impervious to anything except for knife. Won't even burn or melt, so ideal for engine bay wires. For the current they are capable of, size is also better than vinyl insulated. A silicone wire crimped with the correct tool and with sealed Deutsch connectors at both ends will not let you down.

Crimping is not that easy for the home gamer. As I mentioned above, you enter a painful world with cheap crimpers (I have an entire stash of junk) or splash out on something good, but that comes with its own problems. Every car manufacturer has their own terminals, plugs, sockets and it never ends! There's more standards than digital camera .RAW file formats!! Which one to get?! And will you then change all the connectors on the car to that standard? And will you find the terminals?

That is why I chose Deutsch. It's universal, sealed, well represented everywhere, parts readily available, relatively cheap and original crimpers are not a fortune to buy. They are easy to take apart or pull individual wires with terminals on out and put back in with no special tools. Extremely convenient if you know what it means to try and take the wires out of a Toyota or Honda plug. Plus their run of the mill contacts are silver nickel or you can get the top of the line gold ones! Yeah, baby! Don't tell your wife the car is getting gold terminals though.

Which is where soldering comes in. Solder joints are fragile at the transition point between the solder and the bare wire. Copper work hardens easily so if there is a preferred flex point where it will always flex, that point will work harden and break. Soldering creates one such point. The soldered part is stiff and doesn't flex, the bare wire without insulation is now the preferred flex point. Use heatshrink, generously extending either side of the solder joint and you won't have problems.

I used to use a NASA standard solder joint (see here: https://i0.wp.com/cdn.makezine.com/uploads/2012/02/western-union-or-linemans-splice.jpg?resize=514,580) with heat shrink tube. Didn't know it was called that, I came up with it out of despair. Don't worry about the picture being with single wire, it works very well on multistrand.

Silicone wire is probably the best (but the most expensive, of course) here too. It uses so many strands of copper and it is so flexible (ever heard of "wet noodle"?), it is difficult to work harden any particular strand of wire in it simply because there's so may of them and they're so fine. It is therefore unlikely you're going to bend the same wire the same way twice (which is how work hardening happens). It does happen eventually but it will take a long time. If you use heatshrink you will get a joint that will outlast the car and most likely you too.

And if you have solder wick past where you want it to, your technique is not great. I use a high power iron with large chisel tip. I hold it inverted in a stand. Put some solder on it to create a small puddle like a blob and then come in with the bare wire and insert it in the blob as far in as you want it tinned and pull it out. Be quick, not lighting fast but don't dwell. You need to be in and out before the flux loses its efficiency. There will be no excess tin, no wicking no nada. If you have excess tin, refresh the blob, come in with the wire again, the excess will be retained by the blob. If you have sharp spikes you're too slow (left the blob dwelling too long and the flux has evaporated) and/or the iron is not hot enough. Practice.

After that, you can trim it back if needed to how long you want it tinned if you overshot.

And you can crimp it at whatever point you want to crimp it. You can crimp it so the tinned portion doesn't project out of the terminal. And you can add solder to the join after crimping. Again, because the wire is tinned already you can do it in a fraction of a second (tin heats quickly and spreads the heat evenly) and there will be no wicking because the rest of the wire is not hot enough yet to suck the tin along.

I know it's hard when you have two wires barely reaching each other poking out of holes at opposite ends of the dash in the footwell, but believe me, it is possible.

And if it's not possible, just put a connector in line. It will be easier to service!

As for the original post gizmo, I gave up on any auto terminals, just too much trouble. When something needs fixing, it's converted to Deutsch. There are OEM senders, etc that come with their own (generally Bosch) connectors moulded as part of the casing, so I keep a selection of Bosch sockets/plugs for those situations. Bosch connectors are not bad either, so I don't have a problem with those. There are also connectors moulded into globe holders in indicators, headlights and such. If I can solder pigtails I can terminate with a Deutsch plug and pot the soldered end in situ I do that. If not, I don't yet have a solution.

Yep, you are right in everyway. Its unlikely I will ever find the "spare" cash to buy expensive connector and crimpers worth hundreds of dollars. The "solder spikes" I know are due to poor soldering technique. Usually it happens as your trying to splice wires at the same time as holding a soldering iron and solder (so need four hands). The brass joiners listed by haakon will prevent this. You can use the joiner to hold the wire while its being soldered.

seeya
shane L.
 

schlitzaugen

1000+ Posts
If I look back I spent more than the price of a good crimper on crap ones. A deutsch crimper was not available back then but now they are and they have saved me from a world of pain. Get yourself a soldering iron stand (I made my own from scrap lying about) so your hands are free to hold wires. You can also use "third hand" contraptions but again, no need to buy them. And yes, Hakoon's link is useful but I would still advise to use heatshrink over it.
 

PeterT

1000+ Posts
As I said earlier, "spikes" are also caused by crap solder. Eutectic solder freezes instantly, the moment you remove the soldering iron, at 183ºC. There is no mushy stage. I have four different size soldering irons, depending on joint/component size, but only one type of solder.
 
Don't get me started on soldering irons... I had a cheap compact gas/cordless or whatever they're called type I bought in 2005 that was slow to get to temp but worked well for years. Eventually, I lost the 'needle' from it, so had to replace it and have had 3 since that have caught fire, melted or just plain did not work. Sure, all just hobby Jaycar stuff under $50 but I gave up and have since reverted to the old bulky 240v iron that must be at least 50 years old but still works. Even though a Deutsch crimper sounds like overkill for the ever less-frequent auto 12v repairs I might do, god it sounds tempting...
 

DoubleChevron

Real cars have hydraulics
Don't get me started on soldering irons... I had a cheap compact gas/cordless or whatever they're called type I bought in 2005 that was slow to get to temp but worked well for years. Eventually, I lost the 'needle' from it, so had to replace it and have had 3 since that have caught fire, melted or just plain did not work. Sure, all just hobby Jaycar stuff under $50 but I gave up and have since reverted to the old bulky 240v iron that must be at least 50 years old but still works. Even though a Deutsch crimper sounds like overkill for the ever less-frequent auto 12v repairs I might do, god it sounds tempting...

Oh .... you want a superscope. Magic things that create lots of heat quickly. You can buy a 12volt version that will work from a car battery (I have the version that requires a transformer and 240volts).
 

DoubleChevron

Real cars have hydraulics
As I said earlier, "spikes" are also caused by crap solder. Eutectic solder freezes instantly, the moment you remove the soldering iron, at 183ºC. There is no mushy stage. I have four different size soldering irons, depending on joint/component size, but only one type of solder.
great ... more stuff I need to buy .....
 

schlitzaugen

1000+ Posts
Deutsch is most likely overkill, but for us home gamers it is the best option affordability and quality wise. Most good manufacturers like Toyota and Honda use their own plug/socket/terminal design, which is not always water proof but in these cases they stuff the connectors full of some grease I did not manage to find commercially. That works very well. It's something that sticks like the proverbial, it doesn't melt, run, and contacts look factory fresh after many decades. Kudos to them, but I can't for the life of me find that grease anywhere. You can use Silicone grease but that's not cheap at all.
 

1972Ren

The Comeback Kid
Re crimpers: All very well to say 'get the right crimp tool', but that is not as simple as it sounds. There are MANY different types of crimp connectors, and even expensive crimp tools don't necessary crimp any particular one, properly. Which leads on to the next point....

Re wiring: Crimp connectors are also made to suit certain wiring sizes, and to get a really solid crimp, like OEM car loom connections, really needs wire and insulation well matched to the crimp in size.

Re soldered wires snapping: As far as I can see, wire is just as likely to snap through movement induced fatigue, if the connector does not crimp onto the insulation. That is no different to a soldered on crimp. Either way, the insulation needs to be crimped.

But what if I am just joining bare wires?: If bare wire ends are soldered together and have heat shrink over the whole joint, I fail to see how the wire would ever snap at where the solder finishes, as the heat shrink supports the joint.

Re colored crimp connectors: who invented that garbarge?! I stopped using them years ago when I realised that the (poorly) crimp onto the wire, and don't crimp onto the insulation at all. I am amazed that auto electricians use them.

Personally, I've never had a soldered connection break, but have found crimped connections prone to poor crimps, which can be pulled apart by hand, unless the wire, the connector and the crimp tool are all well matched.
 

bob

1000+ Posts
Oh .... you want a superscope. Magic things that create lots of heat quickly. You can buy a 12volt version that will work from a car battery (I have the version that requires a transformer and 240volts).
good one Shane... :)
old-school stuff, had one of these since I was a kid - had to get my own, Dad wouldn't let me use his as he had already destroyed one transformer with a sticking switch on the iron !! they have a tendency to to do this it seems. Protected by wiring a small low voltage globe over the transformer outlet, 6v gives a nice warm glow and lets you know it's working. If you stop using the iron and can't spot the nice warm glow turn it off at the plug, quickly, and clean the internals of the iron assembly.... :)
These units work on the same principle as an RSU (Resistance Soldering Unit), just the gubbins are enclosed to heat the copper tip.
cheers,
Bob
 

jo proffi

1000+ Posts
Re crimpers: All very well to say 'get the right crimp tool', but that is not as simple as it sounds. There are MANY different types of crimp connectors, and even expensive crimp tools don't necessary crimp any particular one, properly. Which leads on to the next point....

Re wiring: Crimp connectors are also made to suit certain wiring sizes, and to get a really solid crimp, like OEM car loom connections, really needs wire and insulation well matched to the crimp in size.

Re soldered wires snapping: As far as I can see, wire is just as likely to snap through movement induced fatigue, if the connector does not crimp onto the insulation. That is no different to a soldered on crimp. Either way, the insulation needs to be crimped.

But what if I am just joining bare wires?: If bare wire ends are soldered together and have heat shrink over the whole joint, I fail to see how the wire would ever snap at where the solder finishes, as the heat shrink supports the joint.

Re colored crimp connectors: who invented that garbarge?! I stopped using them years ago when I realised that the (poorly) crimp onto the wire, and don't crimp onto the insulation at all. I am amazed that auto electricians use them.

Personally, I've never had a soldered connection break, but have found crimped connections prone to poor crimps, which can be pulled apart by hand, unless the wire, the connector and the crimp tool are all well matched.
soldered wires are a common breakage point on musical instrument equipment like guitar amps and leads.
it can always be put down to inadequate strain relief and bad soldering.
I guess the journey in the car is the main driver for these stresses, so now that COVID has taken away any performance opportunities ,is probably a thing of the past!

jo
 

1972Ren

The Comeback Kid
A few personal observations and comments about joints and connectors..

1626362283372.png


Re #1. this is the sort of joiner the OP was asking about. I cannot pull that apart without physically destroying the wires.
They are the easiest method by far for joining wires, and as you can now buy hundreds of them for $20 or so, they get a double thumbs up from me. I note, however, that it is advisable to leave the heat gun on the joint for a good 5 to 10 seconds after the solder softens, as I've found the solder doesn't necessary fully flow into the wires otherwise.

Re #2 The colored insulated crimp connectors are, as noted, junk to be avoided, as they do not crimp onto the insulation. Who invented that?? These non insulated connectors are what I use, for the obvious reason that they crimp onto wire AND insulation, like a proper connector should. Needless to say, crimping to the insulation provides stability and prevents metal fatigue in the wires. The insulating sleeves slip on after. Note: the tangs on the rear crimp are long enough to accommodate fat insulation but I've found need to be trimmed a little for most wire, otherwise there tang folds onto itself in a mess, and not sharply bite down into the insulation

Re #3 and #4. I saw this in a video, and had forgotten about it till reading this thread. Just fold the wire back on the insulation and crimp the combo into both parts of the connector. I cannot pull that apart with my hands at all, and takes a good effort with pliers to rip the connector off. Even then, only because it tears the insulation right off the wire.

Re #5 Alternatively, crimp normally ie wire and insulation separately, THEN spot of solder on the wire end. This will not come off even with pliers (obviously), other than physically snapping the wire. I don't see any way there can be an issue with movement / fatigue breaking the wire as the insulation is crimped. It is, however, fiddly getting the soldering iron in there if you are under the dash!

Note: I saw an add on FB today for soft solder paste which melts with a heat gun but comes in a pot and can be dabbed on (like the solder in #1). That could work alot better while you are on your back wedged under the dash.

Re #6 Folding the wire back as per #3, and then used with the insulated connector can work, as the single crimped part crimps onto the insulation also. You normally need to use the yellow ones, as the red and blue have a crimp tube too small to fit the wire + insulation in. If you do use the yellow ones, however, I cannot pull that apart; it is a very firm connection.

Re #7 I shouldn't really have bothered including it, but the intention was that if one uses those colored PsOS, then squeezing some hot glue in the back should at least stabilise the wire.

Personally, I think folding the wire back and using a non insulated crimp connector is very strong and easily achieved.
 

1972Ren

The Comeback Kid
Re crimp tools
'They' would have you believe that part of The Secret is to get a decent crimp tool.
Personally, I don't think it's as simple as that.

*To work really well, the tool needs to match the connector. Like, same brand. There are many connectors in many nuanced dimensions and types, and if your tool doesn't match the crimp connector really well, often even a reasonably expensive tool doesn't crush the connector hard enough or in just the right way.
*Note that the jaws are not symmetric; one side of them is intended to crimp the wire and the other is intended to crimp the insulation. But different wires have different thickness insulation, so the point where the tool stops at maximum pressure doesn't necessarily crush both parts of the connector optimally. Which can leave either the wire or insulation weakly crimped. And those effing insulated connectors just trick you into thinking anything at all has been done to the rear part. In fact, all you've done is imprint into the plastic.
*Anyway, you have to put the connector into the jaws the right way around, and that isn't exactly obvious.
*Personally, I've found the simpler tool at the bottom of the photo is much more useful, as you crimp the wire, and the insulation, separately, and can feel how hard you are squeezing each. Obviously that is for non insulated. I've had much better success getting both parts really biting down into the wire/ insulation. NB contingent on trimming a little off the rear tabs to suit the insulation thickness.

1626364030472.png
 
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