How install voltage gauge on a 1962 ford galaxie500?

I already install the oil but when I install the voltage one work for a few secons then stop working can it be that it burn or instad it could be 12 volts or 6?

I'm quit sure it is a 12volt that is in your car but have the one you installed in your car remove it and have it checked first to see if it is ok or if it is a 12volt or 6volt