I don't remember wire sizes, but my schematic that I drew up years ago, shows a five amp fuse in my fuse block (buss) for the starter.

L.Adamson
 
It really depends on the size of the wire that you are going to use. The fuse is only there to protect the wire not the device. Mind you if you are using a really large guage wire and the device only draws a very little current it would be prudent to use a smaller fuse.