Kohler K91 Service Manual page 88

Troubleshooting Guide
30 Amp Regulated Battery Charging System
Output tests should be made with engine running at 3600 RPM - no load . Battery must be fully charged .
Problem
Remove 4 Input leads from rectifier-regulator.
Set ohmmeter on Rx1 scale and zero scale .
1 a .
Connect ohmmeter across red leads and
check resistance .
1 b . Connect ohmmeter across black leads and
check resistance.
1 c . Measure the resistance from each stator
lead to ground.
Replace stator If specified values are not
No
found.
Charge
To
2 . Connect leads of flashlight type continuity
Battery
tester from BAT NEG to one AC terminal ,
then reverse leads . Repeat procedure on
the other AC terminal.
3. Remove red lead from REG terminal (ali
other leads connected to appropriate ter-
mlnals) . If unit does not have ammeter,
connect ammeter between + BAT REG
terminal and battery . Start engine and
operate at full speed .
Battery 1 . Remove two red leads from rectlfler-regu-
lator, connect these two leads together.
Continuously
Start engine and operate at full speed .
Charges At
High Rate
ELECTRIC STARTING SYSTEMS
There are three types of starters used in the K
series of engines. The three types are :
Motor-Generator
This starter also functions as a
-
DC generator. In the starting mode, it turns the
crankshaft through a V belt arrangement. The V
belt transmits turning force from a small pulley on
the motor-generator to a large pulley on the
crankshaft.
Wound-Field Bendix Drive Starter
wound starters, electrical current flows through
coils to build up a strong magnetic field to turn the
armature. When the armature starts to rotate, a
drive pinion moves forward on the armature shaft
and meshes with a ring gear on the flywheel . The
armature and ring gear remain engaged until the
engine starts to run . When the flywheel begins to
turn faster than the starter, the pinion is thrown
from the ring gear and returns to the disengaged
position. A small anti-drift spring on the armature
8. 1 8
Test
In the field­
-
Conclusion
1 a . Resistance should be 2 . 0 ohm s .
1 b. Resistance should be
Resistance should b e Infinity ohms
1 c .
(no continuity) .
2 . Lamp off I n one direction , o n when leads are
reversed .
Diodes In regulator are good .
Replace rectifier-regulator If lamp Indication Is
the same In both directions.
3. Charging system output less 20 amp s .
Faulty regulator winding on stator, replace
stator.
1 . Charge rate Is 4 amps or less. Stator Is good .
Replace rectifier-regulator.
Charging system continues to charge at high
rat e . Regulator winding shorted , replace stator.
shaft holds the pinion in this position as the starter
slows to a stop .
Permanent Magnet Bendix Drive Starter
tion of this type starter is the same as that of the
wound-field starter. The major difference between
the two is in the method of generating the mag­
netic field to turn the armature. This starter uses
strong permanent magnets in place of field coils.
Safety Interlocks
In an effort to enhance safe operation of their
equipment , many manufacturers install safety in­
terlocks to prevent engine start before certain
safety requirements are met. These interlocks are
usually incorporated in the starter circuit. U nless
all interlock switches are closed , the starter will
not function .
Before servicing a starter that is reported to have
failed , always check the safety interlock system
first. This is done by bypassing the interlock
switches with a temporary jumper wire .
O.
1 ohms .
Opera­
-