Courtesy and Dome Light Wiring

[jmader]

Originally Posted by 67ChevroletDude

You are on the right path, the dome light is hot all the time and has a switched ground that runs to the door jamb/headlight switch and once the switch knob is turned all the way counterclockwise it completes the circuit. I would verify with a multi-meter that both wires are functioning as they should. From what you describe, the white wire is being grounded somewhere it shouldn't be making the light stay on even when the harness is unplugged from the switch.
This post below is very informative:
https://67-72chevytrucks.com/vboard/...d.php?t=611743

Thanks for the info. It’s good to know my thinking is correct