99 F350 7.3L Diesel

I don't mind fixing things. I fix commercial a/c for a living. It is not so hard when you do it all the time and have the books and diagrams. My problem is I'm not familiar with this truck and if there are cronic problems I should know about.

I just found out that water has been seeping down the front pillar and has gotten into the fuse box. I dried the box out andwhen I put it on the table not so softly a bit of dirt / soot came out of it.I guess I need a fuse box.

Has anybody ever opened the fuse box? I imagine flooded trucks must have these replaced often and wonder how much the cost?

thanks in advance
E.