Strange fuse box
 

Help, I have a 83, 380 SEL. When I open the hood, there is a fuse on the fender above the coil. The previous owner had a piece of wire running across it. My mechanic has not been able to id it, and I want to get it properly fused. It has a cover and what looks like four holes for a plug type fuse. Any and all help or suggestions would be welcomed.