Dashboard overhaul

I have a 1968 Plymouth barracuda. My dash lights are really dim do you suppose that one or other problems 68gtxman suggested might be the problem. Where is the stepdown voltage limiter located. I assume the dash plug should be easy to find, but probably not easy to get to. Being a 60s Mopar Guy ( in more ways than one ) it's hard to see under the dash and work there is even harder. LOL.