Been asked to post some more wiring pics, thought i would post these, show a little that goes into it.
Most way through this connector, wire is Raychem Spec 55, Deutsch Autosport connector, this one has 4x #16 contacts (up to 20A) and 8x #20 contacts (7.5A). Crimped with military / aviation spec DMC AFM8 / AF8 crimp tools with correct positioner to suit each pin/socket. The loops are called service loops, they act as strain relief, so no tension is kept on the crimp on the contact, and also in case a contact does need to be replaced, theres a bit of length of wire to re crimp.
The wire behind the connector is then wrapped with Kapton tape (that gold tape you can see a tiny bit of there, its basically a high heat proof tape, this is to stop any glue / resin from the sealed molded boot that goes on from getting on the wires, also protects the wire from some of the heat needed for the molded boot, so if a repair is needed the molded boot can be cut off and the tape removed then it will look like new and easy to work on.
The looms are made up by twisting the wires in a technique called concentric twisting, were there may be multiple layers, each layer alternates direction, as you can see here, the core is the 4x thick #16 wires, then around it is the smaller 8x #20 / #22 wires, 'filler wires' may be required to fill in that low spot, to end up with a smooth lay, in this case i ended up with a couple filler wires and a couple extra wires were that came along this section to a join that will be in the connectors molded boot, so theres not a big lumpy join in the loom.
As you can see here the end result is a smooth finish, it may then be bound with some Kevlar string, then covered with Raychem DR25 heatshrink. The end result is a very smooth, thin, very very flexible loom that is totally sealed from water, fuel, oil, being aviation derived even de-icing fluid, avgas, you name it.
Pretty much finished, now does on the heat shrink then the sealed molded boot
End result. This is the loom inside my boot.
Another example, this is from my Motec PDM, powers the whole car, the 3 big connector looms come together then joins up into 1 loom.
Installed in the car.