One other possibility is that the reproduction light switch and the old one are not working.
I do not trust repro parts. I replaced a 1963 Impala two speed wiper switch with a original 2 speed switch after the reproduction 2spd switch fell apart ( the wire clips fell off.). I also have/had a repro floor dimmer switch. It would fit the factory floor mount- I am returning it to the e-bay seller (he claimed it was NOS - A/C Delco - it was made in China). We are using original dimmer switches that a friend cleaned the points. Because of these experiences and a number of other repro part problems in the recent past - we did the following for our light switches:
I used a NOS original light switch on my 62 Impala convertible and a nice used original light switch on my friends 62 Impala convertible ( from my stock of 12 + originals).
I think repro parts are getting worse ( after 10 + restorations over the years). If the parts don't work I return them, and get a replacement, or use NOS parts or good used parts...
Sorry for the rant on repro parts but suppliers need to sell quality parts, not junk.
Paul
I guess Im getting too old to remember but I was thinking you twist the knob to dim or brighten the cluster lights and turn it all the way to the detent for the dome light. I know some switches on some cars worked like that.
