I used a 15 amp rocker switch from academy sports. 7 bucks.
Here’s what I’m using...the blue indicated switch controls power to the LS black box which is mounted inside the Craftsman box. If I’m going to make a long run across the lake, or if I’m going to sit at the console and sidescan with my HB Helix, I’ll flip that switch off so I’m not draining the battery on my portable LS. When I’m ready to use the LS again, I flip the switch back on and I’m back online with 15-30 seconds max. I bought that 12V switch/USB/battery meter cluster on Amazon for under $20, and it works great. From some of the reviews I read prior to my purchase, guys are using it in fixed marine applications as well without issue.
I used a 15 amp rocker switch from academy sports. 7 bucks.
Your black box won’t power up until it gets a signal from the depthfinder.
I bought two of these. I use one for my trolling motor and one on the other side coming off of my power battery. Works perfect.
If you have oreilys near by, you can go and borrow one of their lug crimping tools to put lugs on everything to have a good connection. I ended up just buying one off Amazon the second time. I use it occasionally.
Bigby LIKED above post
My black box draws power even with unit turned off