[Healeys] Need a fuse?

[llennep at verizon.net]

Listers,
 
I switched the power for my PU truck shell's interior lights to a hot wire today.  I picked up a hot on a wire (maybe 10 gauge) which is to operate a boat winch.  Formerly the hot was the rear running lights but I wanted to operate the shell light without having to turn on anything (the fixtures have switches).  Q is should I add say a 5A in line fuse to these lights or should I depend on the fuse for the winch system?
 
Thanks for any replies
Keith