Last autumn a boatyard wanted to move our boat but couldn 't work out how to so they jump started it by putting a screwdriver across the ignition relay. Now, at the start of the season, we discover both our 12 volt and our 24 volt alternators are dead. Of course I can 't prove it but my guess is that the diodes have been blown when they ran the engine without turning on the ignition.

Not a great start to the new season. Anyway both are on their way to be tested and repaired so we will see what the official verdict is.

It turned out that it was the external charge regulator that was the problem. This was the top end Balmar MC-624 Maxcharge multistage regulator that had mysteriously died after just 6 years of service. Whole think is sealed in epoxy so cannot be serviced or repaired. Expensive bit of critical kit!