Trailer Lights Help

So I have a 2004 LE and am having some issues with the trailer lights/plug. I cant seem to get power to the plug. My lights used to work fine and then I go to plug up a boat to try out the lights on the trailer and nothing. I unplugged the trailer and checked voltage at the plug and had no voltage at all. I checked the relays under the hood up by the battery by switching them around with another couple relays one at a time and that didn't do any good. Im not sure where to go from here. Any help or advice would be greatly appreciated.