Welcome to the group. The first thing you may want to try is taking a test light and checking the wiring on the rear of your vehicle. Take a look at the wiring diagram for the pigtail receptical on your tow vehicle and check each function. Here is a link to a diagram. http://www.farmbox.com/images/7WayTrailerEnd.jpg
It could be just a blown fuse in your tow vehicle. I've done that before. I backed the boat into the water without disconnecting the lights. I didn't think about it, at least till the next time I towed the coach and some of the lights didn't work. Good luck.
Lowell, Amanda, Marley, and Winnie
1996 T-2053 (First Sunline "Little One")
2001 T-295SR (Favorite Sunline)
2003 F-304SR (Last Sunline "The Big One")
1985 T-1650 (Current Sunline)
2004.5 Dodge Ram 3500 5.9 HO Cummins