On my starboard Yanmar engine
I recently got a continuous alarm
and the displayed error "Alt Error".
Sure enough, the Balmar
is not charging
the system. No measured output from the alternator
. It is spinning and the belt looks fine, etc. No voltage on the field pin.
I (eventually!) found a blown 5A fuse on the engine
fuse compartment. When replacing the fuse, not only did the alternator begin working fine, but the blower fan also came on when power is applied. I hadn't noticed the stbd fan wasn't blowing.
I was surprised to discover the compartment fan was running on the same circuit as the alternator. I assume this fuse feeds to field circuit, obviously 5A is not near enough for the output of the alternator itself.
But now the fuse keeps blowing. Not right away, but after a day or so.
I'm starting to guess the alternator is fine, and maybe the ventilation fan is somehow drawing more current
than it should.
Any suggestions or experience?