What is this and what does it do
 

https://cimg1.ibsrv.net/gimg/www.die...2d34ef79ed.jpg

It comes from the pos. Battery post two of the wires are broken.

Not a Dodge man but would guess they are fusible links.
Anything not working?
You need a wiring diagram and the colours and size (gauge) that is stencilled on them to ID the circuits they supply.
That or they have been bypassed.
Cheers Steve

fusible links,and wires going the fuse box