Yes, #12 will be more than enough...As that can handle more than 20 amps

 

Thanks buddy

 

I agree with Dennis, for something with as big an amp draw as offroad lights, always use it's own fresh circuit, unless of course you are just looking for a turn on lead for a relay, then pretty much any wire would do the trick as there is very little power used. like for my hella back up lights I used a fresh power wire but used the stock reverse wire in the trailer plug wiring for my turn on lead for the relay. So when I hit reverse the relay gets energized and the Hellas come on.

 

Ikeda-san,

How did you route your Amp power through the firewall?

Regards,

Mike