electrical / grounding question

[gpb102030]

On my cd26d i had removed the battery for a few months but before i removed it everything worked fine electicaly. So when i put it back in to day fully charged i got nothing. so i broke out the testers and there was no ground at the battery switch. i started thinking about any thing i could have done. then i remembered i had removed the grounding plate. I am in the process of a bottom job and replacing all of the backingplates. so when i put all of the grounding wires together i had my ground back and everything worked. So my question is this normal. I would have thought that there would not have been a break between the battery and the switch. If a wire ever came loose or corroded in the bilge it could be a little stressful at the wrong time. so what would you do? any thoughs thanks. Greg

[Larry DeMers]

Greg,

I guess that someone grouped all of the grounds together on the grounding plate then? Not a good idea, for the reasons you stated.

Here is what I would do in your case:

There should be a single ground cable running from your battery negative terminal, nothing else. That cable then leads to an above water-line, spray protected terminal strip (Defender), made to accept that ground cables' lug, and also provide numerous attachment points for the various grounding requirements that you have.

This is also where I would attach a wire lead to the grounding plate, but leave the boats 'grounding scheme for lightning' in place on the ground plate. To I.D. this system look for a heavy gauge solid copper wire (~10 to 8AWG), uninsulated in my boat anyway. Leave that system alone and attached to the grounding plate (it provides a shorter, higher amperage path for lightning to take).

Now your grounds will all be above water and out of the spray, so corrosion would be way less. The terminal strip is a convenient and safe way to attach new gear to the ships ground, and makes trouble shooting much easier.

The battery positive terminal should go through some form of current limiting device (fuse, breaker, disconnect) and then onto your DC breaker panel for distribution to the DC devices in the boat.

Hope this helps,

Larry DeMers
s/v DeLaMer
CD30 Lake Superior

[gpb102030]

well i finally traced the grounds. The main ground that went behind the battery switch and the breaker panel was spliced 4 times on its way to the grounding plate. They were copper screw type connectors but the cape dory factory must of used up all there #8 wire scraps off the floor. Then the best thing i found was the cape dory negative bus bar it was a #8 black wire with 6inches of insulation removed and all of the negative wires for all of the light and acessorys were wrapped around (not soidered) to the wire then taped with electrical tape and stuffed up under the head liner . Someone would have to be runway model to have arms thin enough to reach them. I cut away the top of the bulk head over the fuel tank to gain acess. Then i ran my new #8 wire from the battery to the my new negitive bus bar behind the panel and connected all of the boat negatives to common gourd. nice and neat and easy to troubleshoot in the future and much safer. thanks greg