I have a 2003 F150 and the dash lights fuse keeps blowing. Is there a common starting point to diagnose this issue?

 

I am having the same issue. A friend told me it was the head light switch ,so I got a new one, but it still blows #18 the 5amp fuse for the instrument illumination. Its got to be a wire, but I have not found it yet. If I get mine fixed I will reply back with the fix. I have always owned a Ford but never had this happen before.