12V Electrical wiring - wire nuts vs crimp connections

Beg to differ. A FOOL is foolproof. Takes one to know the other.

Another issue is STRAIN RELIEF. This is where terminals fail and they needn't have. No terminal, from the tiniest digital size 30 gauge to 4/0 inverter cable should exert more than a gram or so pull-force on the junction. Long distance wire bridges should use standoffs even if they are home-made 2x2 wood pegs. Those nylon square zip tie mounts are great if a screw or rivet is used. Adhesive back nylon pads should have a dab of GOOP used. Natural color nylon ties and other hardware are inferior. Use black. Stronger, does not weaken when exposed to sunlight or ozone (electrical).

I am not going to argue the merits of crimp vs wire nut or spike vs elliptical crimpers, what I will say is that in both wire nuts and crimp fittings, using the correct size splice for the wires being spliced is important.

I have crimp fittings for 22 AWG to #4 and I have crimpers for all those sizes. I also have wire nuts that were designed for use with two to four #22 wires up to four # 10 wires. Actually the twist on devices I have for #14 and above are generally called Scotch Locs and not wire nuts. Same principle and same rules regarding size.

I also have several "trailer splices", once again size is of the utmost importance.

Use the correct size and install according to the practices for the splice being used.

And finally, nothing is 100% foolproof.

MEXICOWANDERER wrote:
Because there are ZERO regulations RV manufacturers choose the CHEAPEST way to do things. Believe it or not twisting wire ends and taping them would be more costly because of labor time. They would use SPIT if they thought they could get away with it.

Wire nuts are appropriate for things that do not vibrate or hit pot holes. Like a house.

Crimping is the way to go. When I crimp I use a hand crimper with a die that has a spike in it. FAR AND AWAY more secure than elliptical shaped crimps, and no, the point does NOT pierce PVC or nylon terminal insulation. Some myths die hard. Before doubters chime in with their moans, try it out before you commit to eating your words. Something in the formula of the plastic changed around 10 years ago and the die spike no longer splits the insulation. Try it for yourself.

Mex is correct,When I was a comm. tech many years ago the rule of thumb was DC stranded wire with crimp in ,AC solid wire with wire ties
in static situations

The waterproof shrink solder butt connectors are the way to go; a soldered, waterproof shrink wrap you use with a heat gun. Sweet.
https://www.youtube.com/watch?v=d83XuNDnHLI

Because there are ZERO regulations RV manufacturers choose the CHEAPEST way to do things. Believe it or not twisting wire ends and taping them would be more costly because of labor time. They would use SPIT if they thought they could get away with it.

Wire nuts are appropriate for things that do not vibrate or hit pot holes. Like a house.

Crimping is the way to go. When I crimp I use a hand crimper with a die that has a spike in it. FAR AND AWAY more secure than elliptical shaped crimps, and no, the point does NOT pierce PVC or nylon terminal insulation. Some myths die hard. Before doubters chime in with their moans, try it out before you commit to eating your words. Something in the formula of the plastic changed around 10 years ago and the die spike no longer splits the insulation. Try it for yourself.

depends on how much excess wire is available
wire nuts make it easy to replace the fixture, with out cutting and crimping
during MFG production, wire nuts are easier to use than "overhead" crimping, while installing
NEC calls for wire nuts on fixtures , crimping NOT allowed
mfg a mobile residence, the mfg used NEC code, too avoid legal conflicts

i'm not saying NEC covers 12vdc lighting
just saying mfg covered all bases by using ONE standard

for indoor i prefer wire nuts

for outdoor AKA 'car' lighting i use crimps