'65 Dart-Lights flickered, lost electrical, loud bang, car died

Maybe an easy way to understand to understand the electrical path is this:

From the battery the 12V heads in through one or more fusible links to the bulkhead connector on the firewall. On the inside, there's the other half of the bulkhead connector.

Then, the power goes to the ammeter, then the fusebox. After that, you have circuits that go to the lights, without going through the ignition switch, and some that go through the ignition switch to only operate items when the key is on, like ignition, wipers, fan motor, turn signals, reverse lights, radio.

The fusible link is simply a piece of wire that acts like a fuse. When something increases the amperage load too much downstream of the link, it melts and parts the circuit. That just saves the wiring inside the car from going up like a torch.

A very quick test to see whether there is a short inside the car is to take a digital multimeter and select the ohms position. Ohms measures resistance but using the meter it is also an easy way to check whether you have a path to ground when you shouldn't have.

Turn the meter on. Notice when you touch the two leads, the meters goes to 1. or thereabouts. Take one lead and ground it. Take the other lead and probe the circuit that feeds 12v into the car. If the fusible link parted then you will have to get past the link toward the firewall to make this test valid.

Just think of it as completing a big circle. You're starting with ground on the one side of the meter and you are investigating whether you can complete that ground circuit with the other side of the meter because the positive side of the electrical system has shorted to ground somehow.

Think of it this way to make sense of what you are doing: If you take the probes and touch them, the reading goes infinity. You are going to ground one probe and use the wiring circuits to see whether you can complete that same effect, which will happen if one of the wires or switches in the POSITIVE side(which should not ever be connected to the ground side no way no how) is doing something where it is IN CONTACT with the car metal or a positive 12v wire somehow.

If you probe the wire and get no response from the meter then there's not currently a short to ground on the circuit that is past the fusible.

If you get that same "1" reading as when you touched the probes then you definitely have a wire or switch that has grounded somewhere.

You can do that same simple test all the way up those circuits into the car and through the fuse box until you find the particular circuit that has the ground condition in it. Then you can isolate it and make the repair.

One way to do it is start pulling fuses 1 at a time until your meter stops responding. When you pull a fuse and the meter stops responding, there's your affected circuit.

All the help so far has been very useful, maybe this will provide a less intimidating way to approach it.

You need a meter though for sure and don't replace the fusible links with plain wire, you'll burn the car down. You can buy fusible link wire at most parts stores.

Whew.