I know y do it , but why !

wanderingbob wrote:
The reason that I was curious was because I need to run a 20 amp , 12 volt circuit about 15 feet and I have some 12 ga romex , sounds like that might work !
thank ya'll

Yes it will work. Although a repair tech could be misled to think romex is 120vac and reconnect to higher voltage.

I would use more customary primary wire for 12 volts.

http://www.genuinedealz.com/marine-wire/marine-primary-wire