Kohler K91 Owner's Manual page 164

Briggs
&
Stratton Alternator Systems
A
&
RR-Series electric start engines have a single DC output
alternator used for battery charging only. The dual circuit
alternator used on B, LT
&
GT-Series and some C-Series tractors
is actually two separate alternators. A single ring of magnets
inside the flywheel supplies the magnetic field for both of them.
One alternator uses a solid state rectifier and provides battery
charging current. The other alternator feeds alternating current
directly to the lights. Since the two are electrically inde-
pendent, use of the lights does not reduce the charge entering
the battery.
Current for the lights is available as long as the engine is
running. The output depends upon the engine speed.,
s o
the
brightness
of
the light changes with the engine speed.
The current from the battery charging alternator is
unregulated
and is rated at 3 amps. The output rises from 2 amps at 2400
RPM
to 3 amps at 3600
RPM,
and uses less than . 2 of a horsepower.
There is one external connection. The battery charging current
connection is made through one terminal of a two connector plug.
Current for lights is available at the second terminal of this
plug. The plug is polarized to prevent improper connections.
The return circuit for both alternators is through ground to the
engine block.
1. Checking Dual Circuit Alternator
A. Testing Alternator Charging Output
Install an ammeter in Series with charging lead.
Start engine. Ammeter should indicate output.
The charge range is dependent upon the condition
of the battery. If ammeter shows no charge, or
shows a discharge, test stator and diode.
ENGINE RUNNING
3000
RPM
-8-