Stray DC currect gives boat mind of its own?

[WKThune]

Help. This old boat (1977 Carver) has taken over running itself! I can turn on the house water and the battery will appear like it has run down after 20 seconds, I turn off the water and wait and everything is fine. My Nav lights blink on and off some times. The instruments jump all over the place and the bilge pump only acts like it is getting partical voltage. I will hit some rough water and the problem fixes itself. I get back to the dock and it reappers. I have spent hours and hours with a volt meter checking things with no luck. I got mad and hit my instrument panel with my fist and it fixed itself (for an hour). Removed instrument panel and all checked out ok. Bad ground or Bermuda Triangle? any ideas? Battery check Ok.

 

[18rabbit]

Re: Stray DC currect gives boat mind of its own?

BT – Welcome to the forum!<br /><br />About your situation, there isn’t enough info to pinpoint the cause. Right off the bat a couple things come to mind; first, your battery may be toast. It’s possible to meter appropriate voltage when charged but it lacks the capacity to sustain a load like your water system pump. The other thought has to do with the primary power (+) and ground (-) conductors that feed the panel. It’s possible there is a problem in there with either compromised conductor(s) or possibly an intermittent direct short somewhere before the panel.<br /><br />I would start with 3 things: (1) have the battery load tested, (2) thoroughly check the primary panel conductors, including removal for a full visual inspection and ohmmeter testing, inspect all connectors (especially soldered), check for corrosion on the battery switch terminals, etc, and (3) sketch out a rough wiring diagram for your boat, in particular, what’s coming and going through that panel. This will be useful if the primary (+) and (-) to the panel check out ok. With the limited info you posted it is possible there is an intermittent inter-circuit short but I would expect that to flip breakers/blow fuses.<br /><br />Btw, if your nav lights are blinking on/off while the switch is in the ‘off’ position, abandon the boat! I’ve seen the movie “Ghost Ship” and you don’t want anything to do with that kind of a situation.

 

[JB]

Re: Stray DC currect gives boat mind of its own?

I don't think it is stray currents, Cruser.<br /><br />I think you have an intermittent short or an intermittent open somewhere in there. It would require study of a schematic of your electrical system along with a list of all symptoms to pinpoint a suspect connection.<br /><br />The biggest difficulty in tracking down intermittent faults is that they never seem to produce symptoms while you are checking things. You may well have measured the troublesome point when it was not causing trouble.<br /><br />I would completely disconnect part of your system and run the boat, watching for repeat of troubles. If they occur, that part is innocent, otherwise, that part is suspect. By subdividing the remaining suspect portions and repeating, you may be able to isolate it to a small portion of your wiring and just replace it.<br /><br />Good luck.

 

[CTD]

Re: Stray DC currect gives boat mind of its own?

Sounds like a bad connection somewhere. I would start at the battery, check and clean terminals. Follow the bat cable to the starter and clean and tighten the connections there. Disconnect the ground cable and clean it at the block. Then check for where the accessory wires hook up and clean them both ground and positive. You also could have a bad ignition switch with the accessory contacts going bad.

 

[Stumpys]

Re: Stray DC currect gives boat mind of its own?

I agree with the bad connection. It sounds to me like a corroded or loose connection, possibly where the main power comes from the battery to the fuse panel. <br /><br />As CDT says....Alway start from the source and work your way back. Good luck... Troubleshooting can be a pain staking project. I've done it for many years!

 

[WKThune]

Re: Stray DC currect gives boat mind of its own?

Thank you all for the very helpful tips. Give yourselfs a high five! We did find a lose, bad connection and corroated ground on the starboard engine,lose connections at fuse panel, and a relly weird spice in a ground wire that lead to the bilge. I think a TV show called "This Old Boat" would be a hit

 

[97trophy]

Re: Stray DC currect gives boat mind of its own?

conduct an exorsism