bl;
Welcome to the Forum!
When it comes to wiring issues, my first advice is: Let the wiring diargam and
the color codes therein be you guide!
See:
http://sw-em.com/1800%20Wiring%20Diagram.jpg
The wires at the lighting fixture supply power from the (removed) SPDT (single pole, double throw) switch, which switched interior lights to "door" function or constant ON....and don't forget, by lifting the clear lens at the fixtures themselves, lights could also be controlled locally.
GOOD Hunting!