Heres what i would do if i were you. Like kowached said, don't over load your already overloaded circuit. When dealing with anything electrical i always throw in a inline fuse. I've hooked up tons of extras in my Mercedes and My Jeep and there isn't any other way i would do it. This way, if something does get overloaded it just blows the fuse and not the entire electrical device. I learned this the hard way. I hooked up a set of fog lights to the same line as a winch and one day when i needed both of them at the same time. When i started the winch and it fried the entire line all the way to the battery. So be carefull and good luck...

-Biggs