Issue with Wiring & fuses for Lowrance Fish Finder

[abstract3000]

Greetings,

So I got this boat several months ago and with warm weather finally got a chance to get out and look at the electrical as there were stray wires everywhere which turned out to just be some garbage accent lighting that looked like was strung together by a 2 year old. To the point I am looking under the Console at the wiring, and one thing sticks out as one of those "What the hell were they thinking" instances I want clarification on the fix as I am not an Electrical engineer.

There is a Lowrance Elite FS 7 Installed, and I get the idea they were going with, they wired it to a toggle switch to cut the power off to prevent it accidently being turned on when out of water (got it) now how they achieved this is boggling my mind and I'm hoping I'm not missing anything here before i tear this garbage out and re do it.
(by the way it does work as of current)

So From Lowrance -> Black wire spliced and Goes to what appears to be a Ground Bus on a Fuse Block.
The Red Wire is spliced and connected to an 18awg wire that goes into what is stated (30A Inline Fuse) This then connect via spade adapter to a Vampire clip on another unmarked inline fuse, then butt connected to another 18Awg Wire to the Toggle Switch. (You seriously read that correctly)

The other Terminal of Toggle Switch Comes back on an 18awg wire back to the fuse block to what appears to be a 40A Fuse?!?!?

As I mentioned, I am not an electrical engineer, but does this entire system that supposedly guessing was for "Redundancy" defeat the entire purpose all together with those high rated fuses?

My suspicion is I need to simply go From Lowrance (Red) -> toggle Switch for one wire, Then Toggle Switch to Fuse Block and swap the 40A Fuse with a 5A fuse and remove the in-lines all together, leaving the Black(-) wire alone; does that sound correct?

Also another thing out of curiosity, Its a 1998 Hewescraft River Runner 16' boat, and of all the switches on the panel only a few of the options I even have the other switches appear to be wired into a harness for additional features that weren't installed (Similar to vehicles) But the one that just seems off is the "Horn Switch" I checked the anchor locker, and pulled the panels off at the bow, and searched everywhere there is nothing resembling a screen, grill, or boat horn anywhere. I follow the Wiring Harness directly to the Nav lights and there is no other wires or adapters hanging off of it anywhere to "add" a horn at a later date... I'm neither a boat expert does this sound correct? (Just curious on that)

 

[Droid]

I can't see your mess but:
*1st, That depth finder should be happy with 3 amps, maybe 5 if it's some 65" big screen TV type.
*2nd, I find that typically if one tries to buy an inline blade type (ATO) fuse holder all they have to offer are 10 (or sometimes 12) gauge wire. So how do you get a good butt splice between say 12 gauge (should be blue splice) and maybe a 20 gauge (should be red or white)? So I found some 14 & 16 gauge fuse holders online.
*3rd, They do make step down butt splices as in yellow to blue, blue to red.
*4th, the fuse should be no heavier than the thinnest downstream wire is rated for. In your circumstance, you will melt the wires on the Lowrance power harness before you blow a 20 or 30 amp fuse.

Now the horn: Technically you need a horn, be it a built in electric or air horn OR a hand held air horn. I think the hand held is ridiculous junk. Find it while moving 20 MPH or more directly at a collision just a few seconds from happening. If you can't find a horn after following the wires (if wires are even installed from the switch & ground to some point & capped off) then buy a horn & wire it in.

 

[makomark]

Getting rid of the extra junk is always good for electrical wiring...the redundancy described is the wrong kind.

On the unused switches, they are common and sometimes they have harnesses (or partial harnesses) connected, sometimes they dont...they only wsy to know for sure is to trace them out..

 

[abstract3000]

In your circumstance, you will melt the wires on the Lowrance power harness before you blow a 20 or 30 amp fuse.

This was my thought exactly, they are the inline Glass fuse's (the big yellow thing in the second photo)

If you can't find a horn after following the wires (if wires are even installed from the switch & ground to some point & capped off) then buy a horn & wire it in.

Ok, I imagined this would be the case, under the Switch it is wired, and I traced them into a larger loom with a ton of other wires and have no clue where they go from there so I will need to spend some more time looking at that I suppose. I'm just used to Cars where they go into the loom and then for features not installed you find these unused connectors popping out behind the dash, under seats or other places for features not included.

Getting rid of the extra junk is always good for electrical wiring...the redundancy described is the wrong kind.

Thanks, I intended to tear it all out and just re do it without the inline fuses, but the wiring is so Bizarre I wanted to make sure we were dealing with someone wiring while drunk, and not somebody who had a clever idea I had just not heard about...