Fusible link?
Just so we are all on the same page...
A fusable link is NOT a fuse. There is no removable or replaceable fuse. It is a wire that will melt if too much current is forced through it.
Think of it as a sacrificial wire to protect the rest of the wires.
As grjammer said if the terminal connected to the red wire coming from the post on the starter relay then the black plastic cover is missing.
The blue fusable link wire is short, about 6 inches, it goes directly into the bulkhead connector and connects to the heavy red wire that goes to the post on the starter relay.
Red goes into the bulkhead connector
Green connects to the heavy red wire from the starter relay post.
If the fusable link is blown the entire wire will be melted
Btw the blue tag is just an identification marker. It is not a fuse.
This is typical of what a blown fusable link looks like.
Why do you need to know which wire is the fusable link?