Electrical System
41
32 690 01 Rev. D
KohlerEngines.com
BATTERY CHARGING SYSTEM
NOTE: Observe following guidelines to avoid damage to electrical system and components:
● Make sure battery polarity is correct. A negative (-) ground system is used.
● Disconnect rectifier-regulator plug and/or wiring harness plug before doing any electric welding on equipment
powered by engine. Disconnect all other electrical accessories in common ground with engine.
● Prevent stator (AC) leads from touching or shorting while engine is running. This could damage stator.
Most engines are equipped with a 15 amp regulated charging system. Some have a 25 amp regulated charging
system.
15/25 Amp Regulated Charging System
Stator
Stator is mounted on crankcase behind flywheel. Follow procedures in Disassembly and Reassembly if stator
replacement is necessary.
Rectifier-Regulator
NOTE: When installing rectifier-regulator, take note of terminal positions and install plug correctly.
NOTE: Disconnect all electrical connections attached to rectifier-regulator. Testing may be performed with rectifier-
regulator mounted or loose. Repeat applicable test procedure 2 or 3 times to determine condition of part.
Rectifier-regulator is mounted on backing shroud assembly. To replace it, disconnect plug, remove mounting screws,
and ground lead.
Testing rectifier-regulator may be performed as follows, using appropriate rectifier-regulator tester.
To test 25 amp rectifier-regulators:
1. Connect single lead adapter in between B+ (center)
terminal of rectifier-regulator being tested and
squared single end of tandem adapter lead.
2. Connect tester ground lead (with spring clamp) to
body of rectifier-regulator.
3. Connect red lead and 1 black lead to terminals on
open end of tandem adapter lead (connections are
not location specific).
4. Connect remaining black lead from tester to 1 outer
AC terminal on rectifier-regulator.
5. Plug tester into proper AC outlet/power for tester
being used. Turn on power switch. POWER light
should be illuminated and 1 of 4 status lights may be
on as well. This does not represent condition of part.
6. Press TEST button until a click is heard and then
release. Momentarily 1 of 4 lights will illuminate
indicating partial condition of part.
To test 15 amp rectifier-regulators:
1. Connect tester ground lead (with spring clamp) to
body of rectifier-regulator being tested.
2. Connect tester red lead to B+ terminal of rectifier-
regulator and 2 black tester leads to 2 AC terminals.
3. Plug tester into proper AC outlet/power for tester
being used. Turn on power switch. POWER light
should be illuminated and 1 of 4 status lights may be
on as well. This does not represent condition of part.
4. Press TEST button until a click is heard and then
release. Momentarily 1 of 4 status lights will
illuminate indicating condition of part.
Condition
Conclusion
25 amp
15 amp
OK (green) light comes on and stays steady.
Disconnect tester black lead
attached to 1 AC terminal and
reconnect it to other AC terminal.
Repeat test. If OK (green) light
comes on again, part is good
and may be used.
Part is good and may be used.
NOTE: A flashing LOW light can also occur as
a result of an inadequate ground lead
connection. Make certain connection
location is clean and clamp is secure.
Other lights come on.
Rectifier-regulator is faulty and should not be used.
