Enclosed Trailer Wiring Question

[a_garrett82]

how do i get the 12 volt battery in my trailer to charge off my truck?

[parkers30]

the number 4 post on an RV type 7 prong trailer connector should be hot whenever the ignition is on if your tow vehicle is wired right.

http://dodgeram.org/tech/mods/electric/trailer_wire.htm

if that is hot is is just a matter of connecting up that wire from the harness to the positive on your battery.