Very common and very easy to fix. I've had mine done twice it was so easy! Anyway, here's a link to the best thread on this fix:
https://www.ford-trucks.com/forums/4...-gone-out.html
Be sure to click on the red links on post #4 of that thread for excellent pictures of what you want to do. Those resistors are tiny, so I had the electrician where I work do it for me, but any good electrical shop in your area can do it also.