busterking

Great info thank you!

Let me just say thanks for giving me some info on what might be wrong, I'm new on here so I apologize for listing this 3 times I wasn't sure where to post the first 2 times, the 3rd time I tried to make it more clear what I had tried to do, I realize it's almost impossible to track the problem on a forum but I don't have many options, taking the boat to a boat dealer I'm guessing would cost hundreds of dollars that I don't want to spend. I already tried all the YouTube etc. and I do not have friends that fish are own boats.

Can I hook 2 fishfinders and the livescope to a switch panel and then to a one 12volt marine battery? I tried this and the fuse 20 amp fuse which I put in line to the positive post on battery it keeps blowing, can some one help ?