Oh another thing, if you look at the instructions for the Hopkins 42475 it shows that you have a power wire that you need to connect through a fuse to the battery along with the ground wire. Well evidently they haven't updated their instructions after making a revision to the unit. The power wire is now incorporated into the large harness plug and the ground wire still remains seperate. The picture on etrailer is correct, although it only shows four wires going to the inline plugs there is actually five with the power wire and the ground wire is seperate, but the instructions still show that your supposed to route a power wire down through the grommet with the trailer plug, not so.
http://www.etrailer.com/p-42475.htm
If you get one of the other versions that you need a power source use the rear power outlet, that is unless of course you have a trailer with like two dozen lights on it or something. For most campers, boat trailers, utility trailers, you will be fine as if you go over the current rating of the converter that will cut out before you blow a fuse anyway.
I've had my utility trailer for eight years, and this year was the first time i have had trouble with the lights, just a light socket that was plain worn out and wouldn't work anymore. I have had campers, boats, you name it. Never the kind of problems J-T seems to have with his for some reason.