12V Electrical wiring - wire nuts vs crimp connections

Golden_HVAC wrote:
Wire nuts tend to vibrate off in a vehicle while a house is not normally subject to nearly as much vibration, so wire nuts are fine for home wiring connections.

Crimping has been a vehicle industry standard for many years. All the light fixtures in my 1997 Bounder RV are crimped together. I never guessed at why, other than it might cost less, until the vibration problem was mentioned. Crimp on connections usually can not vibrate loose, and therefore are required in most airplane connections that are not a screw clamping the wire to it's respective connection.

Good luck with your project!

Fred.

Yes, wire nuts and vibration do not mix well.. Learned that 35 yrs ago when installing car stereos and constantly having loose speaker connections when using wire nuts..

However, spring loaded wire nuts tend to hold very well and ARE "acceptable" for use in HOME 120/240V wiring so they cannot be all that bad..

My point though is with marker lights, the manufacturer tends to leave very little slack in the RV wire. This typically means you only have an inch or two of slack..

If you use crimp connectors or solder connections, the very next time you need to remove or change the marker you will end up CUTTING OFF the crimp or solder connection CLOSER to the RV. This means you will shorten the wire available for the next connection... You will only be able to do that several times and then you will no longer have enough slack..

I think in this case putting connectors (flat or bullet style) on may be a good choice to allow for removal of the marker in the future (you WILL need to replace the putty eventually)...

When I replace crimp connections that are exposed to the elements on a trailer I find that I have to cut back quite a bit of cable in order to get to good, un-corroded copper. Way more than if the wire was protected from the elements with a good waterproof crimp.

If it needs to be cut it can be cut right at the crimp and should have good copper and not need to be . If there's some concern about length, add wire to make a service loop that can be shortened as needed.

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! :)

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

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

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.

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

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...

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

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.