Peter253 wrote:

Thanks for the tips everyone. I suspect a wiring issue as (I believe),
I should have voltage on the regulator. I have two battery banks, one
that has 2 6volt golf cart batteries for the house, and one separate
marine starter battery that is just to start the engine, nothing else.
I intentionally ran down the house battery to test the alternator.
When I ran the engine and tested the voltage on the alternator, it read
12.42 volts, which was the same as the house battery before I started
the engine. When I switched the control to charge the starter battery,
I read 12.75 volts (the same as the starter battery before running the
engine). So, the alternator reads what the voltage is on the
batteries, but is not charging them.

I'll follow the steps to bypass the regulator to see if the alternator
is functioning. I hope it's wiring issue, that would be a lot less
expensive to fix! If the alternator is out, I fear I've got a bigger
issue because I had it professionally rebuilt about 6 months ago.
So..that would mean something caused it to burn out.

Thanks again for the tips. I'll keep you all posted.

Peter


It sounds likely that you have lost excitation to your alternator.
It normally needs only a few milliamps of current in the rotor to
excite the stator coil. If you can find the field wire and make
certain it has 12 volts connected to it, it may all spring back to
life. You could inspect the brushes to ensure they are feeding the
rotor.

These are small things to fix, and doing them yourself could save
the all up full service complete teardown and replacement of stuff
you don't need.

An alternator rebuild kit is only a few dollars and is a snap to
replace, especially if you don't need to do the bearings or main
rectifiers. It replaces the regulator and brushes all at once. It is
possible you have a single loose connection inside, which you might
snug up yourself.

If you are going to take the thing to an alternator shop, you are
only two bolts away from dissassembling it yourself along the way,
anyway.

What could cause premature failure? A bad repair? An excessive
load? A loose belt or pully slipping? opening the ouptut line while
running at hard charge? Do you have a battery switch? does it have a
field interuptor set of contacts? Those field interruptor switches
are notorious points of failure. When they fail open, your
alternator just quits, becase it gets no excitation. It happened to
me.

I would make sure you have juice at the field terminal, first.

Terry K