400: Battery Warning Light

[smac999]

Originally Posted by transmitterdan

Since the battery warning light/buzzer is on that pretty much rules out another charge source. My bet is the regulator or field wire/fuse. No tach usually means there is no excitation field.

Not true. "Battery" lights are based on an alternator working or not, and nothing to with battery voltage it self. You could have 14.4v on a battery from a solar panel, and you'd still get a "battery" alarm if the alt wasn't excited (working ). And since the battery is already at 14.4v there is no need for the alt to excite. however if you put more loads on the boat, or drained the battery more, the alt would kick in. I have seen it before. But only on fully charged batteries


It really should be called an alternator alarm not a battery alarm. But before solar, battery combiner s etc it would be battery alarm as well

[b_rodwell]

Thanks for your input. In the end I chickened out and asked for the work to be done under engine warranty. The local Yanmar mechanic ended up diagnosing the problem as a faulty battery isolator. It is now fixed with a replacement isolator. It turned out that this is not a Yanmar item but will be covered by the Lagoon warranty.

Thanks again
Brian