It's not a short, a short would blow the fuse.
It's a broken wire, should be easy to fix like DG said.
Get a test light with a sharp point and probe the wire with the park/tail lights turned on until you find a place where you have power and and a place where you don't have power and you have found the break.
It's a broken wire, should be easy to fix like DG said.
Get a test light with a sharp point and probe the wire with the park/tail lights turned on until you find a place where you have power and and a place where you don't have power and you have found the break.