12V Electrical wiring - wire nuts vs crimp connections

[bricetribe]

I have a late 80's Western Wilderness Alpine truck camper which has become a bit of a project.

SEE: http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/27165648.cfm

I am in the process of replacing the clearance lights, tail/brake/turn signals and backup lights with LEDs.

When removing the OEM incandescent fixtures I noticed that the wiring connections were made with wire nuts. I would like to replace these stranded wire connections with standard automotive insulted crimp connections. Is there a reason to not make this change???

Thanks in advance.

[DaHose]

In automotive applications (I'd consider the RV automotive) I have become a fan of soldering, then shrinkwrap and a finish of liquid insulation. Used that method on all my RV connections when I rebuilt the electrical.

I did notice that when I tore apart my RV, the interior wiring was done with crimped on wire nut looking "things". Given that is how the factory did it, I might be comfortable with just crimped on butt connectors and heat shrink when I install the new LED's for the cabover lighting.

I do keep wire nuts on hand for emergency repair, though.

Jose

[mlts22]

Where does one find that proper tubing? One thing I've found with crimps is that there are plenty of cheap terminals. However, finding tinned copper ones that only have one end for the wires, so that the fitting is airtight once the tubing is shrunk into place is a completely different story. Same with crimpers. There are cheapies which make cute little marks but eventually will have corrosion or just pull out due to the loose fit... then there are the type which actually "cold weld" the wires to the fitting in a hexagon pattern, so it doesn't fall prey to vibration later on.

[MEXICOWANDERER]

What amateurs do not understand due to inexperience is that there exists NO DANGER from fracturing with a soldered termination when the termination to wire interface is buffered with correct size 3 to 1 adhesive lined heat shrink tubing.

I've used this process on paintshaker Deutz Diesels that have run for years with a hundred soldered terminations.

But, I have had to use HEAVY-DUTY terminals. They are twice as thick as regular terminals which break at the tongue of the terminal, between the ring and the barrel.

I'll start using wire nuts on other than structures right after I start using Elmer's Glue.

[mlts22]

My concern about Scotch Locks is the fact that they don't give any leeway. If the wires are too small, the connection will be poor. If the wires are too large, and it chops too much of the wire away. Plus, if one reads audio forums, the posters (usually guys installing the new radios and alarms) really dislike those. Add vibration and the narrow contact spot, and this might be asking for trouble down the road.

I think it is a split between crimping and soldering for a marine grade connection, assuming quality tools and materials (for example, the lugs not allowing the wires to protrude, and using a decent crimping tool that makes two crimps, which is important on larger gauge wires.

My only concern with soldering is about vibration, and one has to be perfect doing the work, being meticulous that the solder was at a high enough temperature to seal the joint effectively.

[wa8yxm]

The only reason would be ease of replacement of the lamp fixture.

However given the frequency with which you need to replace sealed LED fixtures....... I would solder and seal with marine grade heat shrink.

[Dusty_R]

In my book the best wire nut is the Scotch Loc.
I've seen some wire nuts that after installed and checked by pulling on the wires to be sure they were secure, would then fall off when I was tucking them it the box to put the cover on.

Dusty

[mlts22]

So far the best I've seen is connectors held on a vice, molten solder poured in, the wires added (while the connector is still heated), then the connector crimped by a tool which does two crimps.. Once it cools down, the excess solder is removed and heat shrink tubing is brought over the connector and put into place.

I'd probably just go the route of using a good connector (one that isn't open-ended), a decent crimp tool, and then maybe even using Plasti-dip to dunk the entire thing and then scrape off the plastic on the electrical contact surfaces. There is still oxygen in the connector, but solder has a nasty habit of breaking if exposed to vibration.

[Jframpey]

Boat trailer wiring... Stripped, twisted and soldered, covered with heat shrink, injected silicone caulk and heated until squeeze out of caulk. Top that!

[MEXICOWANDERER]

This is where I use solder and shrink tubing and a service loop so if the circuit needs a down-the-road lobotomy it makes no difference.

A wire nut that backs off a MARKER LAMP connection can allow the connection to separate, and short. Causing the fuse to fail. Causing the rig to have a blackout in the tail market lamps.

EL SMACKO!

EL LITIGATION!

About thirty years ago I checked on a malfunctioning conveyor engine operating in a pumice mine. I had no electrical because I was waylaid on my day off 20 miles from home on a Sunday fishing excursion.

Battery not charging. Broken voltage regulator wire on a Niehoff alternator on a Dagenham engine. Found a yellow wirenut in the ashtray of my car. Stripped the tiny wire with my teeth. Spun the wirenut on TIGHT TIGHT TIGHT, and the conveyor engine started charging. Tuesday morning bright and early the mine superintendent was banging on my door. An hour later I arrived and found the wire nut had backed off enough to allow one of the two wires to fall out.

Oooooo, Ooooooo, Ooooooo, let's start using NAILS to fix our rigs. Faster and simpler. Gotta work, houses are full of them...

[joshuajim]

WOW... it's a good thing I never drove my sprint car under water 😉

[pkunk]

Under water is more harsh. We used to use Posilock and similar on sub-pump wire splices years ago. It was the most common cause of pump failure requiring pulling the well. Then came crimp connectors & glue swelled heatshrink-problem solved. Many years later under many feet of water, no failures.

[joshuajim]

Back when I was racing sprint cars on dirt, the only connector we used along with most other competitors was Posi-lock. They are waterproof, reusable and don't require additional wire length to connect.

I never had one fail and I can't think of a more harsh condition than racing on dirt.

Posi-lock

[doughere]

I've used numerous wire-nuts on my unit, none of them have been a problem. Properly sized and installed they will be fine.

Doug

[BFL13]

Good point about not having enough slack in the wire to do much with. You get your one chance and that's it. So a way around that is to use your one chance to add some wire.

Then use the new wire added on to connect to the light or whatever, with the connection type of choice. Later if need be you can afford to cut some off to do the replacement.

EDIT- I see the above poster slid in there with the same idea! 🙂