8.20
Section 8
Electrical System and Components
Problem
Test
Conclusion
1. Trace B+ lead from rectifier-
regulator to key switch, or other
accessible connection. Disconnect
it from switch or connection.
Connect an ammeter from loose
end of B+ lead to positive terminal
of battery. Connect DC voltmeter
from loose end of B+ lead to
negative terminal of battery. With
engine running at 3600 RPM, read
voltage on voltmeter.
If voltage is 13.8 volts or more,
place a minimum load of 5 amps*
on battery to reduce voltage.
Observe ammeter.
*NOTE: Turn on lights, if 60 watts
or more. Or place a 2.5
1. If voltage is 13.8-14.7 and charge rate increases when
load is applied, the charging system is OK and battery
was fully charged.
If voltage is less than 13.8 or charge rate does not
increase when load is applied, test stator (Tests 2 and 3).
If the voltage is low and does not increase, and there is
no charging/amperage output, disconnect and reconnect
the rectifier-regulator plug and retest.
a. If the ammeter shows charge for a short time but
then drops back to zero, the rectifier-regulator is
functioning correctly but the battery is faulty. Replace
the battery.
b. If no amperage/charge rate appears during the
retest, go to step 2.
Troubleshooting Guide
15/20/25 amp Battery Charging Systems
When problems occur in keeping the battery charged or the battery charges at too high a rate, the problem can
usually be found somewhere in the charging system or with the battery.
NOTE:
Always zero ohmmeter on each scale before testing
to ensure accurate readings. Voltage tests
should be made with the engine running at 3600 RPM - no load.
The battery must be good and fully
charged.
2. Remove connector from rectifier-
regulator. With engine running at
3600 RPM, measure AC voltage
across stator leads using an AC
voltmeter.
2. If voltage is
28 volts or more,
stator is OK. Rectifier-
regulator is faulty. Replace the rectifier-regulator.
If voltage is
less than 28 volts,
stator is probably faulty
and should be replaced. Test stator further using an
ohmmeter (Test 3).
No Charge
to Battery
3a. With engine stopped, measure the
resistance across stator leads using
an ohmmeter.
3a. If resistance is
0.064/0.2 ohms,
the stator is OK.
If the resistance is
infinity ohms,
stator is open. Replace
stator.
3b. With the engine stopped, measure
the resistance from each stator lead
to ground using an ohmmeter.
3b. If the resistance is
infinity ohms
(no continuity), the
stator is OK (not shorted to ground).
If resistance (or continuity)
is measured,
the stator
leads are shorted to ground. Replace stator.
1. If the voltage is
14.7 volts or less
the charging system is
OK. The battery is unable to hold a charge. Service
battery or replace as necessary.
If voltage is
more than 14.7 volts,
the rectifier-regulator
is faulty. Replace rectifier-regulator.
1. Perform same test as step 1 above.
Battery
Continuously
Charges at
High Rate
Kohler Engine Parts Call K&T 606-678-9623 or 606-561-4983
www.mymowerparts.com
