Trailer lights
 

I HAVE A 2003 EXPEDITION AND LAST YEAR THE TRAILER LIGHTS WORKED FINE. THIS YEAR HOWEVER THE PIG TAIL FOR THE TRAILER LIGHTS HAS NO POWER TO EITHER ONE.THE FLAT PLUG OR THE ROUND ONE.BOTH ARE FORD FACTORY INSTALLED.I HAVE TURN AND BRAKE LIGHTS ON THE VEHICLE COULD THIS STILL BE A FUSE PROBLEM?SOMEONE TOLD ME TO CHECK THE FUSES UNDER THE HOOD BUT I WAS UNABLE TO LOCATE THESE.PLEASE HELP.