Powered Jack for Trailer

[mugwump]

I want to replace my hand cranked trailer jack on my motorcycle trailer to a powered one and my question is: Where does the powered motor for the jack get its power? Do I have to run a separate wire back to the plug or will the trailer motor get its power from the 6(4) pin plug on the bumper if I leave it plugged in? Does anybody know of a less expensive jack? The local trailer joint wants to sell one for $360. That seems a little high to me.

[WildStyle]

Well the one that is on my travel trailer gets its power off of the batteries on the trailer.