I checked 12 volt power at several junctions and found the voltage well within acceptable limits; after starting the engine, charging voltage was fine, and corresponding readings at various points were as I would expect. This was a real puzzle.
To be on the safe side, I left the engine running as we sailed south 3 hours to Grande Anse D’Arlet; that short hop would give us an early morning jump allowing us to beat the mid day trade winds when we rounded the southwestern corner of Martinique for the slog dead into the wind towards Le Marin.
I pondered my electrical gremlin for a couple of days wondering what could have caused the malfunction. I refused to just ignore the issue knowing that sooner or later, the same thing would likely happen again. I thought about Ocean Angel’s electrical power distribution and recalled only one point where all power to the vessel could be interrupted. Many European boats utilize an isolated ground system with a high amperage switch in the main negative circuit as a safety factor. If this switch is turned off, there is no electrical power anywhere because all 12 volt power flows through it. I wondered if the 32 year old switch might have some internal corrosion or pitting that could have caused the issue.
As you probably know, we really like the French islands, and in particular, the harbor at Le Marin on Martinique. After all, we own a beautiful French yacht, and in Le Marin, you can find just about anything that belongs on a boat built in France. A little searching at Caribe Marine and I located the exact 800 amp disconnect switch I needed; no drilling, no modifications – just cut and paste so to speak. The switch was an exact fit.
After installing the new disconnect switch, I noticed our voltage was just the tiniest bit higher at various distribution points. I just might have kicked the gremlin off the boat – for now at least. I think his name is Murphy.