Joining Wires - What's the best way?

[Roundy]

Hi All,

Need to do some more wiring on my car in the future, and wondering about peoples recommendations on joining wires.

Historically I have twisted and soldered wires, then covered with heat shrink.

Doing some reading on the topic, and it seems that there is a school of thought out there that soldering in an automotive application is a bad idea, and crimp connectors are the better way to go.

Looking for peoples thoughts/recommendations on this.

And if crimping is the better way, where is a place to buy the heat shrink crimp connectors?

Cheers
Nathan

[trdee]

crimping is the way to go, but only if you buy high quality crimps and a high quality crimper. the jaycar type stuff is useless. You dont buy heat shrink crimp connectors. you get the crimps and heatshrink separately

[ctrain]

solder causes resistance in the join, if you use to much you cause a high resistance, crimping is good just more expensive, people have different opinions on this subject, i do both as its never caused any issues

[Roundy]

Through my research have seen some people swear about using this style connector: http://www.superiorterminals.com.au/...-Terminals.htm

Basically it is crimp with some internal solder for extra security.

Obviously $$$ but they look a pretty clever bit of kit to me

[Hen]

While the reasoning about crimps having an advantage with vibration etc makes sense, I honestly don't think that a well made soldered connection is going to give you problems in a car. I did my first engine swap and wiring 11 years ago. Most of that wiring is still in the car and has never given issues. I think by far the most important thing is doing it properly (I'm sure we've all seen plenty of terrible car wiring) whichever system you choose.

So if you're starting from scratch go whichever way you want, but if you're standing in the shed and have run out of crimp bits I'd solder rather than stop working

[dnegative]

I can honestly count on one hand the number of soldered joints I've seen in OEM harnesses in the 6 years I've been cutting them apart fixing shit, essentially they have all been solder splices.
If I want to join two wires well;



Cut the plastic shit off and your left with a small ferrule, stick your wires in and crimp them all the way and they are fucking golden. Slide over the glue lined heatshrink and your good to go.
Chopped into and spliced up a bunch of injector harnesses that are twisted pairs (They run 100v at a few amps) that are picky as fuck, never had a drama.

Wiring is still pretty random, I've seen some of the shittiest dodgy work hold up for a decade in the worst conditions with shitty crimps and twist and tape and I've seen beautiful work of art mill spec PVC wrapped harness go bad after a few weeks with intermittent faults. Last week I had a pin back out of a $240 mill spec plug for some reason, thing just dropped out of gear, if it was a plane the **** would of crashed lol

[Cuts]

I've heard that crimps are what people are suggesting.
I've always soldered wires (10 years in the 205 and more overall) and never had a drama.

On the subject of soldering what is peoples preferred method? I do what I call tinning of the wires (so give them a coat of solder first) then heat and join them together.

Watch this video though, he says solder funny and it's not too bad https://www.youtube.com/watch?v=Q9G9gaokqvM

[aus jd 2703]

ideally crimps are the way to go. it is the most reliable method given the right tools and crimps.

how ever for a hobbyist that doesn't need 99.99997% reliability a good solder joint is acceptable.

I soldered my first two ecu swaps an am now contemplating making a harness with all crimps. soldering has worked well but crimping is the next level in a more professional finish (in my opinion).

[Cuts]

One issue I have with crimps they look so untidy. For example if you're connecting wires to existing sensor plugs with old wiring on the plug it leaves a fat lump in your loom.

[o_man_ra23]

Crimps are a preferred method. Either way will give you a point that is prone to breaking where the flexible wire meets the hard join. By offsetting the joins when using a multi-wire loom then binding together with loom tape, you will provide a level of support for this to prevent joint failure.

Another issue with solder that hasn't been mentioned is that it work hardens with vibration, and can be prone to cracking. Properly supported this shouldn't be an issue.

dnegative's method of obtaining a barrel splice is interesting, though could be less than optimal due to the time it takes to remove the plastic for each join (ok if you are only doing a couple). Plus they are generally a closed barrel. An open barrel splice like the one below would be better as you can join a tail off a trunk. Would need a couple of different sizes for different stuff, and you need proper rolling crimpers, but they work great.

http://au.rs-online.com/web/p/crimp-...inals/7187640/

[Daddio]

Crimps are good for those that dont know how to make a decent solder joint...but to make a decent crimped joint will cost a lot more to tool up for than to make a decent solder joint. Also consider that 60 or so crimped joints to an ECU is gonna make for a very fat loom!
(Most OEM joints are crimped because of economics, not because its a better joint)
Personally, I have been soldering all joins for the last three and a half decades without issue (That said, even the bet joins in the world wont help the dodgy Lucas electrics on post war british cars!)

[o_man_ra23]

With insulated connectors I would agree Daddio. But with the non-insulated connectors as found in OEM applications, they are quite a low profile join. They can even be smaller than a solder join. But they do need to be crimped properly, with a proper crimper. That said, the $8 crimper I bought from Jaycar 15 years ago is still going strong (the $120 ratchet crimper I got recently has other advantages...)

As for your statement of economics, with modern manufacturing techniques, solder is cheaper in manufacturing, but crimp joins are still preferred.

At the end of the day, if you can solder well, but can't crimp for shit, then solder. If you can crimp, but can't solder well, then crimp. If you can't do either, then I would go with crimping (quicker to learn), and crimp a few offcuts before trying the real thing.

[oldeskewltoy]

I too am in the crimp camp.....

but I'm a stickler for the right kind of heat shrink - dual wall, glue lined. This not only provides great support, but provides a hermetic seal.

[trdee]

yep glue lined heatshrink is the way to go.

wiring can become real expensive when you want to get quality stuff! all depends how far you wanna go...

[egamirrorim]

When I did the auto electrical short course a few years ago the younger teachers were all about crimping, however, we learned soldering anyway as its a good skill to have.

How expensive should my crimp tool be for "good crimping"? I think I paid about $125 when I was in the course.

Also, I've not been able to find this glue lined heatshrink in consumer level quantities, can anyone point me in the right direction? I don't want wholesale amounts...