I think the light switch doesn't cancel power, it makes ground.I dont know on your model but on my 57 the PO had grounded the housing and then hooked up the light to dome (power all the time) on switch so it never shut off. There was only one wire run to it. :confused: He just left the bulb out. After I ran a ground from the light to the front terminal on the switch and put the bulb in it worked correctly.

"Do not walk behind me, for I may not lead. Do not walk ahead of me, for I may not follow. Do not walk beside me either. Just leave me alone, you're starting to freak me out."

1957 GMC 150