I have done it before----
to do it right-- it's actually pretty involved. I just added a couple of step downs to my guages, installed a 12v generator and put a low amp 12v battery in??? It worked just fine for over a year until I sold my '54 Chev.......

Of course to do it right......

I would recommend the Top Secret guide to 12v conversions. Speedway motors carries it.


Hope that helps.