Attention: TDR Forum Junkies maybe someone has the answer I need, as near as I can determine the factory towing package has only a 18 gauge wire from the truck battery to the trailer connector for charging the trailer battery while travelling, however, sometimes on my trips it seems that if I start out with a fully charged trailer battery it is drawn down some by the time I arrive at my destination, this seems to indicate that the 12 volt circut isn't a charging circut at all!! but probably is just a dumb battery to battery connection, anyone have the technical expertise to give me a clue about this?? 
