Is there a way of sealing the fuse box on a 04 650? It seems to have alot of corrosion in there. And I have been blowing fuses alot.

 

use a calk gun LOL

 

After youre done riding for the day, leave it exposed to the air, so it can dry out. Once the moisture is gone, the corrosion will stop. You could try spraying wd40 on the fuses and in the box, or using some dielectric grease on the terminals.
If you seal it up tight, the corrosion will get worse...it needs air ciculateing to dry out.