We have an original equipment Sharp convection microwave, model R-1874F, in our 08 Thunder.  While using it a couple days ago, it suddenly stopped working, no power.  I checked the power to the outlet and it was good.  I finally found the internal 20amp fuse which was blown.  I replaced the fuse and power was returned to the unit.  Shortly after turning on the microwave the fuse blew again.  
I have an extended warranty on the coach, including the microwave.  I am presently in Mesa AZ.  Anyone have a suggestion on who to contact in the area to get the microwave fixed or replaced while taking advantage of my extended warranty?