Making electrical connections

Sorry to discredit your work but those two methods of wire repair are terrible! The first one should only be used in a dry environment and as a last resort, soon as moister or water gets in the cable will rot! As for soldering it is a very poor method of wire repair and shouldn't be used in the automotive industry, there are to many variables that people don't understand, like the type of solder that should be used, the type of flux that should be used, the tempeture of the solder bolt and the condition of the wire. Solder shouldn't be used on can bus wiring either, as recommended by most car manufacturers. Putting a bit of tape around it as well is pretty poor, if you are going to solder which I recommend against then at least use heat shrink to give a water tight seal. The heat shrink also grabs the insulation of the cable give the solder joint more strength.

If you are going to do any sort of wire repair, i would recommend using a Duraseal crimp splice connector. As showen in the image below :


All you have to do is bare back both ends of the wire you wish to join and using the correct crimping pliers (not the cheap thin crap ones but the ratchet ones) squash the terminal, then heat both ends until the plastic shrinks down and glue comes out and your are left with a professional fit and forget repair. I always put an extra bit of heat shrink over the crimp as well, but that's just professional preference, looks better and twice less likely to get water in.

This is just me professional opinion, it's up to you what repair you wish to do. But I work in a garage dealing with electrical repairs all day. I would say 75% of the work I do is repair a previous repair that someone else has done poorly ( like soldering). If a jobs worth doing.....

Nice format and images though, if you could make one for the Duraseal connectors then that would be great. Also really like the heads up display!

Afternoon all,


Thanks for the feedback!

Brungle/Bog

You can't buy scotchloks that you'd want to use from Halfords. There are two different types of scotchlok available - dual-blade and single blade. Single blades are rubbish and Halfords only sell the single-blade items.

Here's a source for the dual-blade type: (suitable for 22 to 16 AWG or 0.5mm^2 to 1.5mm^2 - which is fairly typical for 'interior gadgets'

CONN TAP 22-16 AWG RED - 558 (BOXED)

You can also ask 3M nicely for samples. Friendly BT engineers use 'goop filled' double-blade versions for telco work. They're largely waterproof, but only in smaller sizes.


Jenga_89

I hear you! I should probably have quoted a bit more from the original thread and included the link:

How to make electrical connections

The bit quoted below is the important one; I was thinking specifically of interior gadgets when writing the guide. The scotchloks aren't the biggest evil in the world in that particular application and have the great advantage of being difficult to get badly wrong.

Which method is best?

Soldering, followed by self-amalgamating tape, followed by insulating tape, produces the best joints but requires the most skill. This is recommended for exterior joints or joints subjected to oil/vibration/heat/dirt/moisture.

Soldering with insulating tape is ideal for interior use as you'll make far less mess with the plain insulating tape, and there isn't really any oil/dirt/moisture to damage the joint.

Wire clips are ideal for beginners, because you can't cut yourself, burn yourself, cut things on the car, melt things on the car, or make a joint that can short-circuit when using these clips. They are only for interior use though; on low-current cables that aren't subjected to oil/dirt/moisture/vibration. Do not use these clips outside the vehicle, in the engine bay, for high-current loads, or anywhere there is vibration.

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Soldering

As for soldering it is a very poor method of wire repair and shouldn't be used in the automotive industry, there are to many variables that people don't understand, like the type of solder that should be used, the type of flux that should be used, the tempeture of the solder bolt and the condition of the wire.

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It's probably fairer to say that soldering is very sensitive to operator skill. (soldering is really only out of fashion in aerospace because of cost: unskilled labour + crimps is cheaper). Otherwise, it's stronger, lighter, and neater than a crimp.

If you're patient but poor (hobbyist) I think it's a good choice as you can connect almost anything to anything without carrying a large stock of parts. Practice and the right iron/solder is needed though.


Heatshrink

Completely in agreement. Heatshrink is better, preferably 3:1 shrink, adhesive lined. A dab of hot glue inside just before you shrink it to seal the gaps between the wires (8) on the double side helps. You can't wire-tap with it unless you cut the OE wiring though, so I think you're safer with the tap and PVC tape for internal stuff. (again, written with internal use only in mind)


Crimps

If you are going to do any sort of wire repair, i would recommend using a Duraseal crimp splice connector.<snip>
if you could make one for the Duraseal connectors then that would be great.

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Insulated terminal crimps are an '0' crimp. This isn't as good as the double B crimp (better still, a 4-indent/hex crimp) that you find in OEM wiring in my view, especially on the smaller wire diameters. You get far more extrusion of the wire stands and voiding with a 0 shape crimp - both bad things - which reduces the security and longevity of the crimp. The wires creep into the voids at either end of the 0 over time, relaxing the joint; turning a round wire into a flat end over-stresses the strands at the side of the connector whereas on a B or indent/hex crimp the forces are even; the muck and moisture creep up the voids.

The Duraseals are the best '0' crimp out there - the heatshrink keeps the muck and bullets out and helps stress relieve, because the heatshrink is soft it doesn't interfere with the crimping too much, and being clear you can see when the wire is inserted/joint is crimped correctly. Throw a good ratchet crimper at it and you've got a pretty good solution that's quick and not too operator skill dependant.


Folks must never ever confuse them with these pieces of junk though:



These are evil. Opaque plastic prevents you from seeing the wire and either interferes with the crimp tool or splits and falls off. There's no strain relief whatsoever, and plenty of space for much, dirt, and bullets to find their way into the wire. Folks usually crimp them with this type of tool:

http://wiki.diyfaq.org.uk/images/a/a5/PoorCrimpTool.jpg

The joint lasts long enough to put it all back together and turn on the power before one of the cables drops out and, uninsulated, sets fire to something...


I don't use the duraseals myself (don't own a ratchet '0' crimp) but if you were able to email me some good photographs of how to make various joints (a splice or two, with varying/mixed wire diameters, plus an end termination with or or multiple wires) I'd be more than happy to make it into a 'comic' style guide and cite you as the photo source.


Bare crimps are my favourite. These you can double B-crimp, then solder to fill voids/seal/stress relieve, and finally heatshrink over it. On end terminals slide your insulating boot down over a dab of hot glue, heatshrink again over that to tie the boot to the wire, then fill with spray grease/contact grease to keep muck out before connecting it up. Overkill perhaps, but it does mean that the wire always breaks before comping free of the connector.


Cheers,

--
Marko