Splicing wires doesn’t seem like it should be rocket science. Touch one bare wire to another, make ’em stay together, and you’re off joyriding in your uncle’s hot rod at 3:00 a.m. But as it turns out, splicing wires can be rocket science, with even NASA formulating standards for how to securely and safely make these connections. Nevertheless, gearheads continue to employ a variety of different wire-splicing methods, insisting theirs is the strongest or the most conductive or the most resilient. So let’s semi-scientifically determine which is the best.
For this test, I’m considering just straight splices—wire to wire—and not any sort of tap, crimp, or plug-in connectors. (Splice versus crimp is a discussion for another day.) I’m also looking at low-voltage automotive wiring, not household or small appliance wiring, and focusing on the splice, not any covering like heat-shrink tubing or electrical tape. While many kinds of splices exist, I’ve narrowed down the test methods to four, all of which are commonly used in auto repairs. I’ll evaluate each on the tensile strength of its mechanical and soldered connections, and I’ll make a note of other attributes, including aesthetics and how the splice affects the wiring itself, all of which is 20- to 22-gauge and comes from my Nissan Leaf’s harness.
Let’s introduce the splices:
Instructions: Strip a half-inch to an inch of insulation from both wires. Give each wire’s strands a light twist to keep them from splaying. Lay the wires parallel with the bare ends side by side. Twist the exposed strands together
Wire Color: white
This is the simplest splice, typically capped with an orange wire nut and shoved behind a dashboard. We’ve also seen it referred to as a Pigtail Splice, but aren’t pigtails curled?
Palm Frond Splice
Instructions: Strip a half-inch to an inch of insulation from both wires. Splay each wire’s strands into the shape of a palm frond. Lay one set of splayed strands atop the other. Twist the strands together.
Wire Color: yellow
Also referred to as a Wedding Splice, this method provides many points of contact between the individual strands.
Instructions: Strip one to two inches of insulation from both wires. Cross the bare strands about a third of the way up. Wrap each bare wire around the other at least three times.
We all have our black boxes—things we’d rather not tinker with because we don’t know how they work and don’t want to know how they work. As long as the black box is doing what it’s supposed to do, it’s easy enough to leave it alone and focus our resources on other things. If it’s not working, we replace it or hand it off to somebody who knows what they’re doing. Having black boxes is nothing to be ashamed of; it’s just an acknowledgement of your limitations.
Electro-modding an old car—specifically, thinning out a wiring harness—will quickly reveal every black box in your life, both literally and figuratively.
Thinning out a donor car’s wiring harness is a matter of removing unnecessary circuits before transplanting the bundle into your project car. In my case, for my Chenowth EV, I won’t need power door locks, power windows, or a rear defroster, so why keep any extraneous wiring? It adds weight and complexity, but more importantly, the less wiring I have to sort through, the easier it’ll be to diagnose the issues that will inevitably crop up when I get to the put-it-back-together-and-make-it-work stage.
But, as with any modern vehicle, eliminating wires is not easy. Black boxes abound. Circuits might meander from one end of the harness to the next. The wiring might be discrete, but the functions it carries out are often far from obvious, even if you have a factory wiring diagram.
Still, it needed to be done, especially if I wanted to continue with my plan of using all of the stock components necessary to drive the traction motor from the donor Nissan Leaf using the Leaf’s traction battery. So, to make sure I didn’t screw up anything or get overwhelmed, I developed a few strategies for this weeks-long process.
1. Label everything. I’ve seen people use subtler labels than green masking tape, but subtle would be self-defeating to me during this process. I needed to see at a glance what a group of wires did and where they terminated. Even when I identified and removed an unnecessary circuit, I labeled it where I clipped it (and on both sides of the connector, if it ran through one), just in case I needed to refer to that wire stub later on
.Just as important, I removed pretty much everything that the wiring harness plugged into from the car, even if I knew I wouldn’t end up using it. That air-conditioning compressor above obviously makes no sense in a sand rail but still serves as a good reference. This strategy has proven particularly useful for the steering column and the various controls mounted to it.
After the shock of the early delivery I started to take stock of what I had bought as it’s always a gamble buying sight unseen even with pictures.
Joe had left some start and stop instructions in the car which were really helpful and the title was also in the car
Managed to get the car started and reversed the car out of the garage, pretty hard to move as the brakes were stuck on to a degree and the handbrake cable was inoperable and I’d hazard a guess never worked. I’ll come back to the brakes a little later.
Upon opening the hood I found that the car had been fitted with a Pertronix electronic ignition replacing the points. Another point to note was the state of the wiring. As suspected I was looking at a little bit of an unfinished project. But on the bright side the car ran well.
An initial look at the underside showed some rust mostly surface but some work needed on the usual inner wheel arch area
The interior looked good and appeared to have a LeBaron Bonney interior kit fitted
There are still quite a few items to take care of on my Model A. Managed to take care of one of these today. The Pertronix electronic ignition hadn’t been very well fitted which resulted in the module that arrived with the car failing. One of the issues was that the conduit for the distributor wiring was missing. I managed to source one and fitted it today after putting it off for ages. It makes things look a neater and more authentic.