what are these two larger wires, (red and black) for that come from the steering column?
ignition switch?
The red wire (always hot) takes current from a splice that connects with:
1) The one side of the ammeter (the other side being the wire from the battery)
2) The alternator feed wire
3) The battery probe in the bulkhead connector (always hot)
The black wire takes power from the red wire inside the ignition switch (when key on) and gives current to a splice that feeds:
1) The windshield wipers
2) Accessory probe in the bulkhead connector (key triggered)
3) Voltage limiter inside dash
Does anyone have a factory wiring diagram for the steering colum harness?
That's a 1972 one. you still need more if you want to know where some wires end to...
More detailed diagram (1972 one also)