I bought a lowrance 3x for my Jon boat. The wiring diagram shows a fuse. Do I need this fuse for using a 12v 8 ah?

My Elite 4X install manual says 3A.  It should have come with a fuse and holder.  To answer your question, yes, you need it.

Mine didn't come with the fuse or holder. Thanks for the info.

? ? ? Did you buy it new?

Yes just got back from big r where I bought it. They opened two more and none of them had fuse or holder. 

I love lowrance finders but these directions stink.

Hmmmm.... sounds like budget cuts.  Your 3X is what my 4X was in '14 and it came with one.  Heck, the Elite-4 HDI I just bought from West Marine (great sale price too) for my Lure 11.5 came with one.  

If you have a Radio Shack, or even car stereo shop near you, you should pick up a waterproof fuse holder and a couple of fuses.  It's always good to keep some spares.  Your local auto parts stores will also have them, but often charge too much for them.

Good luck.

 

Thanks