Technical Soldering automotive wiring

Post 25, this thread....

 

The bottom line is that there are best practices and worst practices.
IMO
Best practice is a crimp on end using a calibrated ratchet crimper for the specific terminal. A B&T or Klein plier crimper is also excellent and with a little practice makes an excellent crimp more pro electricians use these than anything else in my observation. As noted many have made solder connections that have lasted for years.
Worst practice is crimping on the wrong side of the split, using crimpers made of sheet metal, using the wrong size end, piss poor soldering etc.
I love my 3M ratchet crimper but is slow and hard or impossible to get into tight spots.
Also use a good wire stripper.
Dan

 

That is a great tip!

 

I worked with a guy who "identified as a mechanic" that graduated from the university of you-tube that told me after wiring a set of power running boards on a brand new jeep, "you know the crimps don't hold the wire, the shrink tube does" I went back and redid every connection.

 

Thanks Steve for the great thread. Excellent, learned a few things!
Dan

 

Not mentioned yet, what about " alinox", or whatever gel it is, that you are supposed to use in household wiring for dissimilar metals, aluminum terminal with copper wire, should that be under the crimp, as in...what is the silver colored coating on most connectors. Brass connector, but plated with what?

 

I don't know how true it is but in the aircraft world supposedly there is no soldered connections except on circuit boards because the wires can become brittle and obviously it's critical at 35,000 ft just under Mach 1.
Myself in my cars at home I usually use butt connectors and shrink wrap and just like everybody else said I prefer to have the ones without the plastic because you can get the shrink wrap over the top of them and it shrinks down really nicely when it's done it's almost invisible on less critical connections like maybe an amplifier inside a car I will just use a regular crimp connector, usually with no shrink wrap although I'm trying to break myself of that but no matter what or where I am doing the connection I do give the wire a good tug to make sure that it is really secure in there.

 

I guess I do things differently. I do agree a rigid mounted solder connection will break, but how many automotive wires are rigid mounted? For high amperage circuits, solder is superior, checked with thermal camera vs crimp its a difference. Wire nuts are the worst. You have to get copper wire stupid hot to become brittle. A general solder iron should not get that hot unless your using a gun. The key to good solder joints is a hot iron, and quick heating of wires and solder flow fast and clean, should be a good shiny finish when done.

Crimping, alot of guys use the proper insulated crimp tool, I have found that to be worthless, most folks do not crimp or have enough ass to crimp that with handheld tools to get correct yield. I use the non insulated one, this yields a huge mechanical advantage, and if you are heat shrinking after, any damage to the connector done by this method is nil.

Butt splice recommendation is the kind that has the heat shrink insulator built in, it seals up the connection and no need for additional heat shrink.

All battery terminals are soldered, and shrinked.

For doing Cloth covered wiring, All solder butt splices, all ring terminals same, heat shrinked.

 

I think that's also a key factor, because soldering like you would pipework using an open flame often oveheats the wire (as evidenced by the copper turning that dirty purplish-red color) which will cause the metal to not be so flexible and fracture in time. A lot of people will still solder small wire joints using this method and then wonder why they fail.

 

The crimpers Moriarty showed where the very same ones I used to repair the shattered bundle of wires om that F102. I was given them to use from the Hanger tool crib, as I said they were so good I swiped them for myself, still have them and use them often here soom 60 years later.

 

I agree with most of your post! And I’m a solder guy! But….I still crimp every terminal, especially the battery cables. After crimping, I heat the terminal with a torch and feed in solder until it will not hold any more. I try to used the correct size terminals. It takes a special crimper. I use this method after I was convinced to use a set of cable made by a local truck parts company, that failed.
Here are some pics of my battery cable crimper.




Bones

 

I had a car that for 2 frustrating years would sometimes charge, and sometimes not. Multiple people couldn't figure out the cause. It turned out to be a loose crimp. Since then, I crimp, solder, and heat shrink wrap EVERY connection that I possibly can. I ain't no theoretical Electrical Engineer, just a lowly Industrial Engineer who has to make things actually work.

 

For you hard-core solderers out there, go and read this if you haven't already... Technical - Crimping Tutorial | The H.A.M.B.

We have basically three options when it comes to 22-10 AWG sized crimp terminal choices; insulated barrel types, uninsulated barrels, and Packard types. I use the uninsulated barrels wherever possible and the above tutorial will show why.

All the barrel connectors I've ever seen are made of tinned copper (the tinning is for corrosion resistance) and the better ones have the barrel seam soldered. Sized correctly for wire size and crimped with one of the recommended crimpers, these are as foolproof as it gets. I've never had one fail when done right, and that's including 35+ years in the electrical industry. In the rare cases of catastrophic failure from extreme overcurrent or a loose connection creating heat, you may find the terminal end or the wire burned off, but the wire inside the actual crimp will still be there. These have two shortcomings. One, no built-in strain relief. Shrink tube will take care of this as addressed in a previous post here. Two, because these were developed for industrial use, not automotive, there isn't as great a selection of terminal ends compared to the Packard types. In most cases there are workarounds, but not always. Where you'll run into issues is with some plastic plug connectors where they need to 'latch' in.

For you guys worried about corrosion 'wicking' in through the bare exposed end, rather than soldering try this... Loctite 1525607 Loctite Aviation Gasket Sealant | Summit Racing A dab on the open end will seal it nicely. I use this on my battery terminals also. Everything needs to be spotlessly clean bare metal (no remaining corrosion) but do it right and you'll never have to clean them again. Slather it on thick (more than one coat is better), making sure it's fully sealed. Easily touched up if it gets damaged by jumper cables or whatnot...

Last, Packard style terminals. The OEMs love these, for a variety of reasons. First is cost, these are cheaper to make and use less-expensive brass and in some cases steel. The better ones are tinned, but don't seem to be common. Because these were developed primarily for automotive use, there is huge variety of ends available, although you may have to hunt to find some of them. Another plus is built-in strain relief, although the aftermarket doesn't do so well with that. The main problem with these is getting a proper crimp plus usually needing more than one operation to have finished crimp.



This is a typical 'generic' Packard style crimp. This is NOT what the OEMs use. The difference is the strain relief on the ones they use aren't just simple 'flaps', theirs come to points and curl over and stab into the insulation for a superior firmer grip. Where the main problem for us comes in is we don't have access the precision crimpers that the OEMs use. There are probably dozens of manufacturers who make these crimps, all with minor variations which can be critical. The OEMs have theirs made to their own spec and use big-buck (multi-thousand $ each) precision pneumatic crimpers that can do both crimps in one operation. Best case for us is use a name-brand crimp with same-manufacturer-made crimper, but those aren't cheap either. So we're stuck with whatever 'generic' crimper with cast rather than machined dies that may be recommended by the harness supplier or try to hunt something down on your own. These pretty much require two operations, one for the wire, the other for the 'strain relief', two chances to screw it up. It can be crapshoot finding a crimper that will work with the specific crimps you have. It also doesn't help that sloppy quality control on the crimps can introduce yet more variations.

I use these once in a while (as little as possible) so I did buy a couple of crimpers for them. One was a POS, I threw that one away. The other can do 'OK' but is very finicky to use and not all crimps meet my standards when done. These I did solder in many cases, but more time used. I've since changed my method, cutting the strain relief off and modifying the wire flaps so I can slip a barrel connector over the remains. These crimps I trust....

 

It’s funny as Im a soldering double shrink tube guy ( first shrink tubing with color to cover connector second shrink tubing in clear to cover label)
As I’m talking to a buddy who is also a soldering guy told me his new soldering issue and now a crimping guy.
Newer cars can’t be soldered at all joints as they used wire wrap around the strands and also send signals down the wire. From what I was told solder blocks the signals and causing other issues. I found that interesting..

 

One of the issues with using insulated butt splices is you can't easily see where the split is inside the insulated body, so you might be opening that split when crimping. It's easy to know where the split is on connectors as it's always the front side.
But I prefer bare connectors either way as once the heat shrink is applied they just look nicer and are smaller.
As for solder, it can become molten if things go wrong and whatever the wires feed goes into an overload situation and begins to heat the wire. I've seen cases like this where solder actually ran out of a connection when the wiring got hot enough. A dead short trips the fuse or breaker quickly, but a high amperage overload slowly heats up the wiring and the solder is the first place to fail.

 

Which is precisely why it became illegal for use by the National Electric Code...
A loose connection will do the same thing.

 

Agree, there are alot of variables in terminals and quality/design of the crimp tools. I probably have 6 or 8 crimp tools. I have found one that does the wire crimp and strain crimp in one step. I use it a lot when wiring up relay holders. It has a stepped depth barrel and if the terminal is correctly inserted does a nice job on both crimps.

 

That is why I always crimp before I solder. Then the hot terminal actually draws the solder in, using very little solder! If you have seen solder “ run out “ of a joint, I wager it was not crimped, wrong size terminal and too much solder! Just my opinion.
But folks there was a huge thread on here about this subject, batted back and forth.

Crazy Steve put on a thread , wiring 101 , I believe and maybe one on Crimping vs soldering , . It was a great thread and warranted reading, for anyone serious about doing a good job wiring their vehicle!


Bones

 

I don't see any need to solder if you make a good crimp. What does it add to the connection that makes it better?

 

Pretty much nothing.... You'll be hard-pressed to find a solder joint in an OEM harness outside of electronic components.

 

I don't want to take this thread off in another direction, but will briefly mention this about terminal variations. Just one example. So, you need to add a Bosch style relay. You get a relay holder, some 14-16 gauge and some 12-10 gauge wire ends with the female receptacle for the relay, and the correct gauge wire. What could possibly go wrong? Well, are all of your parts compatible? What!?? Some relay holders are set up for the crimped terminal to load from the top, and others from the bottom. So the wire terminal lock tabs are different. On the picture below note the direction of the lock tab. One locks if loaded from the bottom and one locks if loaded from the top.

o

 

OEM's don't solder automotive wiring.

Heck, OEM's do not solder communications satellite, or launch vehicle wiring.

You do you, but if you think that soldering is somehow necessary, you are quite wrong.

 

HUH? Electrical engineer here. We use adhesive-lined shrink tube on terminals such as rings and spades. It helps to reduce migration of water up the conductor and - most importantly - provides a strain relief for the conductor.

We see more failures from wires breaking at the back of those crappy insulated (and non-strain-relieved) terminals used by some of our component suppliers than we do with the properly crimped and heat-shrunk uninsulated terminals on the harnesses we design.

 

chicken, one of the guy's in our club had a '40 Ford with an intermittent problem where he would loose his headlights every so often. Every time he put a meter on the terminal strip it showed he had voltage to the lights. He climbed under the dash asked a fellow club member to yell if the lights went off. He started tugging on each individual wire and the feed to the headlight pulled right out and the shrink sleeve was the only thing holding the wire in the wire end.

 

One reason OEMs don’t solder is, it’s cheaper to crimp! In OEM always look at the bottom line first. OEMs also wire their cars with the absolute smallest wire that will meet minimum standards. You wire your hot rod like that, it will fail!
I will admit, after reading Crazy Steve’s many , many posts on this subject, that a “ proper” crimp is all that is necessary! I try to get a proper crimp and think I at least get close, most of the time. But I come from a long successful history of soldering after I crimp. Most terminals I crimp , then hit with a dab of solder on the eye side of the crimp, with a big iron. The solder disappears , looks like it is pulled in with a magnet, to the end of the wire and barrel housing. To me, that just insures sealing any malformation in my crimp.
I know I’m beating a dead horse, but after 45 years without one failure attributed to my process, it is hard for me to give up my ways!
That being said , I no longer advise folks to solder, like I once did!
Actually, my last wiring project…..I did not solder. I am appalled!





Bones

 

yah I know its not a Space Shuttle. But there are good guidelines in the NASA workmanship standards, usually with pictorials of acceptable/unacceptable. Easy to Google. Keep a copy of relevant standard handy, helps to explain and win arguments.

 

friend of mine runs a truck/equipment shop and stopped soldering wiring. He found any solder joint exposed to the salt spread on the roads would make the joints rot. He told me he would cut the shrink tube back and there would be green fuzz . He thinks the solder reacts with the salt.
Any body else seen that ?

 

Even the flux inside the solder wire gives you corrosion if it gets humidity and time. So if you want to be bullet proof first crimp, solder only the crimp, clean up with denaturated alcohol and cover with glue inside heat shrink.
If you want to save time an effort get the right crimp tool then heat shrink and add a dab of corrosion protect grease so no humidity gets into the stranded wire from the terminal side.
Crimping is faster and more reliable than soldering and it’s easier to be done fully automated by machines, that’s the reason the industry does it.
Have you ever seen one of these machines doing stripping off the insulation and crimp in fractions of a second, this would be difficult and more expensive with solder.
The key of a proper crimp is the right amount of pressure applied to the material. The compressed area must be gas tight after the process.
But on the long run with humidity and salt a little bit of grease sealing this makes a different. Why doesn’t grease the industry? It’s not intended for their products to survive more than 10 or 15 years and the grease will disturb the clean processing area.

 

I found this to be helpful and simple...

 

The Thomas and Betts crimpers are awesome. Crazy Steve recommended them in his wiring-101 thread, and I imported a pair from the US. He is right - they make a repeatable crimp that will not fail. Took me from a "most of my crimps work" to a "confident in what I do" person. Thanks again Steve.

I suspect Jim is right - soldering or crimping can work, provided the person doing it has skill and patience.

A question for those who solder old wiring harnesses please. Most of the stuff I play with is GM Holden factory wiring that dates to the 50's and 60's. It's PVC coated, multiple strand wiring. The wiring is generally in good shape, insulation color still bright, not oily, insulation flexible. I can strip the insulation easily enough. The copper is rarely bright after the insulation is removed. I understand the basics of soldering - clean wires, heat wires not coil of solder, solder should wick in, allow to cool, joint should have mechanical strength. I can solder two new wires together without many dramas. I still struggle on a lot of the old harness soldering. The wires do not seem to want to wick up the solder.

I've tried:
a) tinning each of the two wires first the joining the tinned wires (often can't get the wires to tin).
b) using resin core and non-resin core solder. The solders are for wiring, and come in coils.
c) heating the wire a little more (to the point the insulation starts softening).
d) heating the wire a little less.
e) cleaning the wire strands with abrasive paper until they are bright copper.
f) cleaning with abrasive paper then thinners.
g) spreading the wire strands slightly.
h) twisting the strands to tighten them slightly.
i) cutting the wire further and further back to find "a good piece".
j) making sure the soldering iron is clean before starting.
k) changing soldering irons (a poor tradesman blames his tools).
l) changing solder suppliers.

I still struggle to get the old wires to wick... this then made me a "can't solder for sh$%, better learn to crimp properly" person. Appreciate views on what I am doing wrong with the soldering please.

Cheers,
Harv