Humminbird Piranha Max 215 Powering up issues

[cj5jeep80]

Hello, I am at a loss as to what's going on with my fish finder. I bought a Humminbird Piranha Max 215 last year and was working fine on my other boat. This year I installed it on a 15ft ski boat that I rewired myself. I started with a fresh marine battery, 20 amp fuse and ran 12 gauge wire to a block terminal at the bow.
After hooking up my bilge pump and running lights to switches, I hooked my fish finder`s power cable directly to the block terminal as it powers on with it`s own switch.
My bilge pump and light work fine but I get no response from my Humminbird. I then tested the voltage at the block...12.6 volts....I tested the voltage on the 2 pins of the fish finder`s power cable and I get 12.6 volts....Plug it in and.....Nothing....So then I removed the power cable from my boat and brought it inside to test on a small 12 volt battery I use to power the electronics on my kayak..I began by testing the voltage of my small battery and it read 11.3 volts. I hook my Humminbird up to it, and it powers on perfectly fine.

How can I get no response on my boat while hooking the power cable(with a reading of 12.6 volts at the pins) and yet the same power cable hooked to a weak battery(11.3 volts) and it works perfectly....I`m really stumped!
Any help would be greatly appreciated. Thanks Rick

 

[GA_Boater]

Welcome aboard.

Electronics take 12 volts as you verified. But did you hook up the ground and is it a good ground source?

 

[cj5jeep80]

Yes I beleive it`s a good ground... I separated the 8 screw block terminal in half using jumpers, 4 red (positive) and 4 black(neg) coming straight from the battery

 

[cj5jeep80]

I have a black negative wire coming from the battery to the bow feeding half the block(black side), and a red positive wire coming from the battery feeding the power (red side)on the block

 

[GA_Boater]

Run a temporary ground from the battery to the H'bird. Bypass the power block. Or hook the FF up to the power block connections for something that works

You may have a bad connection on the wire between the battery and power block.

 

[cj5jeep80]

Yes okay....I will have to try running a separate wire from the battery as you suggested. I did also try fastening the wires quickly to a working connection but I still have no power up.
If the ground on the Neg bus is bad, I wonder why my bilge pump and lights seem to work fine? Would they not be affected also as they are hooked up to the same block
Anyway, I can't thank you enough for your help. Really appreciate it
I will certainly try to get to the bottom of this problem this week end and I will let you know

It is very kind of you to help people as you do, Thanks again Rick

 

[GA_Boater]

We try, Rick.

While you have the long wire to check the ground, meter for continuity of the grounds feeding the block from the battery.

What I'm thinking is one of the 4 pairs, 4 power& 4 grounds, of wires from the battery may have a bad crimp.

It is confusing that hooking up to a working circuit didn't allow the FF to power up.

 

[cj5jeep80]

Well I found out what was wrong.....I ended up trimming off about 12 inches of wire from the Humminbird's power cable and it now works correctly,
There must have been a break or a weak spot in the cable, well...I feel much better now.
Thanks again for all your help. Great forum