Fish finder wiring questions

[Bigpetah]

Noob here and I'm not very sharp on wiring. I have two unused 8 gauge wires running from cranking battery compartment in the stern to the bow. I want to hook up a Lowerance Carbon unit on the bow. The unit says to use a 5 amp fuse.
1) Can I utilize the 8 ga wire that's already ran?
2) If so, where in the positive wire do I place the fuse?
3) I have a hole to mount an on/off toggle switch, would this be good so the unit never draws power when not being used?
I'm sure I'm missing something.

 

[Chris1956]

8gauge wire is much heavier than you would need for a FF. You can use it however. it is more appropriate to use it to power all accessories, current and future.

However, I like to wire in a master accessory switch at the helm, so I can turn all accessories off with one flip. Saved me from a bead battery more than once.

 

[mike_i]

"I have two unused 8 gauge wires running from cranking battery" It would be better if you connect it to a house battery if you have two batteries.


2) If so, where in the positive wire do I place the fuse? as close to the battery as possible.

3) I have a hole to mount an on/off toggle switch, would this be good so the unit never draws power when not being used? It should not draw current when the unit it off. If you have a battery switch you can turn it off to disconnect the batteries.