Steve Neale

Ok, more info. On pre heat the alarm sounds and the warning lights come on. Once the key is turned to start, the engine turns over, fires and runs. The lights go out. On checking with the multi meter (this is our only battery monitoring) the alternator is pushing 14 volts into battery. Everything fine and dandy for a time with no problems . Then perhaps a couple of weeks later once you have started the engine you hear the pre heat alarm and see that the warning light is on. No output to the battery. We suspect that this is a problem preceding our ownership as some months after buying the boat we twigged that the alternator wasn't working and spotted that the spade end connector to the warning light on the back of the alternator had been disconnected so there were no warning lights (and therefore it wasn't charging). We have one starter battery and two domestic separated by a manual switch. We have been told that this could be caused by turning the key to OFF before pressing the stop button, but the last time it did it, we are sure that we pressed the stop button first. Any help would be appreciated.

Update on my original problem. I took the alternator into a reputable auto electric place with a view to replacing it and left it with them so they could source one with correct fittings etc. Called in there today to be told there is nothing wrong with the alternator! They had tested it and it works fine. When I get a chance I'm going to fit it and see if it's behaving itself. Looks like I'm going to need an expert to get to the bottom of this. Thanks for the tips.

Thanks for the replies folks, already some good tips there. Bizzard sounds as if he knows the same auto electric place as I've just been to!

Since acquiring latest boat last summer,I am having serious alternator problems. I have now had the unit re-conditioned three times and it has just stopped working again. The auto electrician (the latest one) reckons he can tell if the fault is on the boat rather than the alternator itself if I let him have a look. Do I trust him? Not sure. Batteries have all been replaced, cabling and wiring seems ok. It is a Betamarine engine with what appears to be the original alternator labelled 55amps. Any ideas anyone?