The old wiring really is scary- the kind of thing you often find in a 42-year-old Detroit beater you got for free. How about heavy-gauge wire splices made from ring terminals held together with a screw and "insulated" with crumbling electrical tape? The horror!
But new wiring stuff costs money, and these poor bastards have the misfortune of frequent garage visits by a LeMons judge, who is sure to jack up his bribe requirements to stratospheric heights if he catches them blowing past the 500-buck spending limit. Mr. Astro is an electrician, however, specializing in wiring up office buildings, shopping malls, etc, so he has the solution…
DIN Rail and terminal blocks! He's working on wiring a hospital now, and some new equipment came with DIN rail terminal blocks in European-spec colors (you can't use the wrong colors- somebody might get zapped) so into the trash bin they went. Hooray for scavenging your race car parts from a dumpster!
This stuff is great- you can just keep stacking blocks on the rail, with as many inputs as you like and there's no problem adding new stuff- attaching wires is just a matter of poking a screwdriver into a slot and inserting the wire in the correct hole. The green blocks are grounded to the rail, which is screwed to the car's body. Want to add a police siren and an ooogah horn? Easy!
First, the guys who like to think things out before they start cutting holes in the car- that seems kinda weird, but whatever- make a wiring plan.
A couple of rails mounted behind the glovebox door will provide power to instrument panel items. Note the street-sign mounting plate.
The Black Metal V8olvo team donated our car's unneeded fusebox to the Belvederians (one of our team members works for a transit bus manufacturer, so we have a nice free bus-grade circuit-breaker box in our car), and the Volvo 240 unit turns out to be an excellent universal fusebox (as long as you don't mind those funky European ceramic fuses). Here it is mounted on the dash; the wiring will go through that split-loom-edged defroster vent.
For brake lights, fuel gauge sender, and weird trunk-mounted secret weapons, there's another wiring outpost mounted in the rear of the car. Note the handy wiring diagram drawn in Sharpie on the sheet metal.