3, IMO is too small for a winch. My xd9000i warn will pull 400+ amps at maximum pull rating and over 200 amps pulling 4,000 lbs.
I'd go at least 2 gauge or thicker. Warn specs out a 2 from the factory. If a longer run of wire, for sure go up in thickness.
Sent from a a few tin cans and some string.