Help me confirm my suspicion

I'm attemping to fix some problems the PO made while wiring.

Here is what I HAD:

Hummingbird depthsounder/fishfinder wired so when NAV lights were on, it shut off.
VHF wired in a way that when IGN was on, it turned off (No good)

I removed the old VHF to install a new class D, and in doing so wanted to wire it properly. So I pulled 12v from the blower switch (though now that I think about it, I pulled 12v after the blower fuse) it appears the fuse bank for switches is wired from the ign switch.

NEW VHF and hummingbird are sharing the 12v+ the hummingbird is using the existing ground off one of the gauges. The new VHF is using a ground in another place.

with Both hummingbird and VHF on, and key turned on, VHF turns off while hummingbird remains on.

Do I simply have a ground issue with the VHF? I'd just like to confirm before I yank all the access panels out again.

Thanks!

Re: Help me confirm my suspicion

Yikes!

None of those items should be attached to the ignition switches or the gauges. You need an entirely separate electrical system consisting of 8 or 10 gauge leads from the battery to a fuse/circuit breaker block and negative buss. Some fuse blocks have the negative buss integrated into them, simplifying things a bit. Each accessory should then be wired to its own fuse/circuit breaker and negative("ground") spot on the buss.

Re: Help me confirm my suspicion

Amen to what NYBo said.

You need a seperate positive fuse/relay block and ground buss. All the accessories get power from this block and ground through this buss. This is the only way to be certain that everything is getting adequate power and a proper ground.

You'll have to be certain to turn everything off at days end, or put a kill switch somewhere in the wire feeding the power block and just shut it all down when you are done for the day. Be sure any kill switch is rated at or above the maximum amp rating of the power block.

Re: Help me confirm my suspicion

I figured the easiest (and safest) thing to do is run a new lead for a fuse block and ground buss. The odd thing is the gauges, switches and existing fuses still appear to be factory wired from Sea Ray. Each switch is piggybacked from the other for 12v+ and the - is piggybacked across the G terminals on the gauges.

Re: Help me confirm my suspicion

That's not unusual, my '97 Starcraft was wired the same way. They set it up to carry the load it was shipped with and anything else you add should have it's own source of power coming straight from the battery. If the accessory load is going to be significant you should run a second "house" battery.

On my pontoon I have the outboard and the anchor/running lights on the cranking battery, nothing else. I run the stereo, fish finder/gps, livewells, bait tank, phone charger, house lights, everything else off a seperate battery that is tied to the cranking battery via a Yandina combiner. The combiner will electrically tie the house battery to the cranking battery to share the charge from the outboard if the cranking battery is above something like 12.8 v. If the cranking battery gets discharged to about 12.2 the combiner will seperate it from that house battery, thus preserving the cranking battery to start the outboard. You can float, relax and enjoy your music, etc. all day, knowing that your cranking battery won't be run down and not start your big motor because of running accessories.