Voltage drop at ballast resistor

That's why I boiled it down to a simple, do this, instruction.
What 67Dart273 has written is all good. After you get up to speed, it will make sense when you come back and read it over. I understand you're not there yet.

If there's any part of my instruction that doesn't make sense or isn't clear, let me know.
You will have to figure out which cavity in the bulkhead has the connectors for each of those lines.
If it's not obvious on the car, then look at the factory diagram in a service manual.
- Second choice is an aftermarket diagram like these MyMopar - Mopar Forums & Information - Mopar Wiring Diagrams 1972 to 1976
First try to trace them on the car itself.