The Vintage hot rod wiring kit divides the whole car into sections, each with the wires, terminals, loom, and a wiring diagram for that section in a bag, such as the "Turn, Tail, and Parking lights." ...

Automotive Mil-Spec wiring is derived from the standardized and certificated wiring that is used in Military and Aerospace applications.

Always keep an OE service manual handy to access the wiring diagrams for your vehicle's exact year and model/sub-model due to wiring differences between models.

It should go without saying that you need the factory wiring diagrams for your car to do any of this; sometimes you can find them online, sometimes you have to buy a used factory shop manual on eBay.