dome lights not working, fuse? switch?

my 63 cargo vans dome lights arent working, i traced the wire to under the dash and when attached to 12 volts the dome lights come on. i checked the fuses i could see (3 on the light switch. and turned the light switch all the way to the left and wiggled it).

i assume the dome lights are turned on by the light switch knob being turned all the way to the left right?
and there is probably a fuse somewhere (if so where is it please)

at this point what is the best way to diagnose the problem?

thanks

My van had the same problem, and a new light switch took care of it. Check the wiring: www.vintage-vans.com/67fordwiring3.html -shows the dome light wiring.

Is your instrument lights working when your lights are on? It could possibly be a fuse. If they are working it is something else. I would suggest that you test the output where the bulb goes with a tester to see if there is any power going to it. You can buy a little tester at autozone for under $10

thanks i now will have a good reference to go by
dont have power at wire from switch to domelight wire
dash lights work fine
will pull light switch and check those contacts

yea i am going to pull the switch out tonight and look it over
thanks

contacts on switch corroded, cleaned and fixed, thanks!!