In the Navy we never soldered any wires, only crimped. Take a piece of wire and crimp one end and solder the other. Place each end in a vice and wiggle both ends and the soldered end will break. Also, don't put shrink sleeve over the end. If a wire parts at the joint, the shrink sleeve can hold the wire to the electrical connector and cause intermittant problems. Get the best crimping tool you can find and the joints will never fail you. This topic has been discussed before and the crimp guy's think they are right, and the solder guy's think they are right, so do what you feel is best for you.
What these cords are made of is called 'SO' or 'SJ' cord and the cable can usually be purchased in bulk or cut-to-length quantities at better electrical suppliers. IIRC, the SO has a rubber outer insulation (like welding cable) and be very flexible, the SJ will be vinyl and won't be. The rubber will retain it's flexibility longer but isn't as abrasion/cut resistant. Neither type likes heat, keep it away from heat sources as much as possible. You can also get different sizes (all the same in one cord) from #18 up to #2, as well as different numbers of wires; 3, 4, 5 conductor cable is fairly common, above that will usually require special order and a minimum unless possibly if there's a lot of large industrial businesses in the area. Make sure you seal the ends well, as these will transmit/hold liquids like a hose if they're present.
Any trailer supply place has wire by the foot inside a sheath with 4, 5, 6, etc. wires inside. Made to wire trailers and withstand weather.
Yes on the soldering, and heat shrink, it will take a while longer but you won't have the problems of wire pulling apart or loss of full power flow to your electric components. Very wise thing to do.
Good thread with good ideas. Wiring [cars] still bugs me. Ive worked on and around everything on my 56 F100 avoiding the wiring.
I would suggest using shrink connectors (ANCOR is a very good choice), I have used them many times, and had very good luck. They are a crip style connector, but the shrink ends also contain a glue. Once they are crimped and heated they not only provide a water-proof seal, it is virtually impossible to pull them apart. I agree with previous posts, a good set of pliers (and strippers) is of utmost importance. I use Channel Lock 909 crimpers, and Klein 11063w wire strippers, both very good, durable products that will make quick work of it. Whether you use a wiring kit, or make your own, I would also suggest using relays for all your heavy draw items (headlights, cooling fans, etc), this will let you avoid having to use as much heavy guage wire. One other thing I have always done is running all grounds to a ground block (wired directly to the battery) instead of grounding items to the frame, body, and firewall. This does require a lot more time (and wire), but if you make a schematic of your ground block and have a problem, you will know exactly where to look. Hope it helps.
...with regards to my previous post, yes, I use the rubber sheathed cord and sometimes buy it buy the foot at home supply outletslike Menards, etc....and I always seal the open ends to keep out moisture, etc. ...good points.
i'm just dropping this off, theres some good reading there. http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
These are pretty cool zip ties, with a Christmas tree push clip. 1/4 inch hole mounting, would make underdash routing very simple. https://www.belmetric.com/toyota-c-12_688_690/d12286-toyota-clip-p-5642.html
Its a standard toy*ta part, this is just one listing. I'm sure if you looked thru auveco catalog you can buy them in bulk. I got a bag of 100 from work, they were spare engr samples we used for electrical harness routing, we did pull testing on them, pretty strong. I know they are available on the open market. We tested a few sizes.