Alternatives to those pre insulated butt joints

For some reason, the motor trade favour soldered joints insulated with heat shrink sleeving.

This is out of step with the rest of the electrical world, where soldered joints are considered at best a bodge, at worst a breaker of regulations.

Whichever method you use, if done properly it will be reliable.

Chris

Solder & heatshrink, or the duraseal buttcrimp with integral heatshrinks work well. You'll need both sizes though. Tycos all in one heatshrink & solder rings are quick & reliable.

Generally the main objection is they're expensive & need highly skilled labour.

We're talking inside a dashboard. I've got no itching desire to start wafting a soldering iron around the inside of my car. Perhaps the best way forward would be to buy a multiconnector thing. It'd mean a load of crimped spade joints, but at least it's pretty tidy compared to a rats nest of butt joints of uncertain crimp quality - having used non-insulated crimps, pre insulated ones seem like a massive bodge.

There's a religious war going on over this :-) You can get uninsulated butt crimps & heat shrink them.

Because they work.

Really? Then why does every bit of electronic kit in my house have soldered connections? Why was I taught to do it in my HND Electronics Engineering?

Who mentioned electronics? Oh, and there are loads of crimped connections inside every PC I've ever looked at... :-)

Had you taken an *Electrical* Engineering course, you would have found that soldered in-line connections are deprecated.

Chris

Try these:

Permanently? twist the wires together and cover with insulating tape.

It doesn't. Look at all those multi-way connectors inside your PC - crimped connectors clicked into a plastic housing. Look at the connections through your phone line - crimps or IDCs for nigh-on 30 years now.

Solder's OK when it's new, but it's slow to make and doesn't last well with vibration. Aerospace used it into the '70s, but only by individually stress-relieving each pin with a tight rubber sleeve and a pair of virgin pliers.

because you're ancient.

That's to stop the inevitable loose strands shorting.

All the aftermarket work I've seen tends to use pre-insulated crimp types which I hate. If you mean OE looms there's very little soldered on those. Sometimes where several earths are grouped together.

A soldered joint will usually be fine provided there is strain relief far enough away from where the copper has heat hardened.

Yes. Crimped connectors on a car will also give problems after a time if in arduous conditions.

How the hell do you "heat harden" copper?

IIRC if you heat copper and let it cool naturally, it becomes "work hardened", but if you plunge it in water to cool it rapidly, it becomes ductile and workable.

I'll start that just assoon as I've finished puking.

I'm not sure what your definition of aftermarket is; all main dealer electrical work I have seen has been soldered. If the AA use any means to make an electrical joint that is not soldered, they ask the customer to sign a temporary repair disclaimer form.

Of course, a crimped joint needs the same sort of consideration also.

My experience is more from industry with filling and packing machinery. There are many similarities with the environment found in cars WRT movement, vibration and potential liquid contamination. IME, a soldered joint in these conditions is more likely to fail than a crimped one by a factor of perhaps ten.

Chris

If you work it (hit or bend it) it becomes work-hardened. There's no heat-based process that hardens it.

Copper, unlike steel, is a (relatively) pure alloy and it only has one phase. The heat-based processes on steel work by moving carbon in and out of solution and by changing the phase that the steel grains are in (i.e. martensite, austenite etc.) -- you can't do that to copper. All you can do with copper is to mechanically damage the crystal lattice, introducing dislocations that make it stiffer and more brittle. Heating relaxes these dislocations and restores the undisturbed lattice, making it soft again. Because this is a lattice change, not a phase change, it just doesn't matter if you cool it slowly or quickly afterwards.

VAG have been the opposite for years, I can't speak for any of the others

You can't, flexible cables snap next to the soldered joint the same way they snap next to the strain relief in a 13A plug.