can't figure out
 

Have a 2003 f250 lariat super duty with the 6.0L diesel. ..on way from wyoming to Phoenix Arizona I went to use my tow haul button cuz I pull a 40 ft fifth wheel. ..when I poked the button on tow haul it quit working as well as my 5 outside cab lights...I've checked all the fuses to many times. ..I've believe it's from a relay switch or something. ..anyone know which one and where it's at?